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Keyword	Definition
14 CFR 121 (Air)	Code of Federal Regulations, Title 14, part 121. Prescribes rules governing the operation of domestic, flag, and supplemental air carriers and commercial operators of large aircraft.
14 CFR 135 (Air)	Code of Federal Regulations, Title 14, part 135. Prescribes rules governing the operations of commuter air carriers (scheduled) and on-demand air taxi (unscheduled).
1-Hour Ozone NAAQS	The 1-hour ozone national ambient air quality standard codified at 40 CFR 50.9.
23 CFR 420	Planning and Research Program Administration
23 CFR 450	Planning Assistance and Standards
23 CFR 460	Public Road Mileage for Apportionment of Highway Safety Funds
23 CFR 470	Highway Systems
23 CFR 500	Management and Monitoring Systems
23 CFR 652	Pedestrian and Bicycle Accomodations and Projects
23 CFR 710	Right-of-way and Real Estate
23 CFR 750	Highway Beautification
23 CFR 751	Junkyard control and acquisition
23 CFR 752	Landscape and Roadside Development
23 CFR 771	Environmental Impact and Related Procedures
23 CFR 772	Procedures for Abatement of Highway Traffic Noise and Construction Noise
23 CFR 777	Mitigation of Impacts to Wetlands and Natural Habitat
23 CFR 940	Intelligent Transportation System Architecture and Standards
23 USC 134	Metropolitan Planning
23 USC 135	Statewide Planning
23 USC 149	Congestion Mitigation and Air Quality Improvement Program
23 USC 162	National Scenic Byways Program
23 USC 202	Sllocation of Highway Trust Funds for the Federal Lands Highway Program including the IRR Program.
23 USC 204	The administration of the Federal Lands Highway Program including the IRR Program.
23 USC 206	Recreational trails Program
23 USC 217	Bicycle Transportation and Pedestrian Walkways
23 USC 505	State Planning and Research
25 CFR 170	Tules for the administration of the IRR Program by the Bureau of Indian Affairs (BIA).
40 CFR 51	Requirements for Preparation, Adoption, and Submittal of Implementation Plans; Subpart T-Conformity to State or Federal Implementation Plans of Transportation Plans, Programs, and Projects Developed, Funded or Approved Under Title 23 U.S.C. or the Federal Transit Laws; Section 51.390, Implementation Plan Revision
40 CFR 52	Approval and Promulgation of Implementation Plans; Sections 5230-5234, Sanctions
40 CFR 93	Determining Conformity of Federal Actions to State or Federal Implementation Plans
42 USC 61	The Uniform Relocation Assistance and Real Property Acquisition Policies for Federal and Federally Assisted Programs
42 USC 85	Law regarding Air Pollution Prevention and Control
49 CFR 17	Intergovernmental Review of Department of Transportation Programs and Activities
49 CFR 18	Uniform Administrative Requirements for Grants and Cooperative Agreements to State and Local Governments
49 CFR 19	Uniform Administrative Requirements for Grants and Agreements with Institutions of Higher Education, Hospitals and Other Non-Profit Organizations
49 CFR 20	New Restrictions on Lobbying
49 CFR 21	Nondiscrimination in Federally-Assisted Programs of the Department of Transportation-- Effectuation of Title VI of the Civil Rights Act of 1964
49 CFR 24	Uniform Relocation and Real Property Acquisition for Federal and Federally Assisted Programs
49 CFR 26	Participation by Disadvantaged Business Enterprises in Department of Transportation Financial Assistance Programs
49 CFR 27	Nondiscrimination on the Basis of Disability in Programs or Activities Receiving Federal Financial Assistance
49 CFR 29	Government Wide Debarment and Suspension (Nonprocurement)
49 CFR 32	Governmentwide Requirements for Drug-Free Workplace (Financial Assistance)
49 USC 53	Law regarding Mass Transportation
8-Hour Ozone NAAQS	The 8-hour ozone national ambient air quality standard codified at 40 CFR 50.10.
A.M. Peak Period	(See also P.M. Peak Period) The period in the morning when additional services are provided to handle higher passenger volumes. The period begins when normal, scheduled headways are reduced and ends when headways return to normal. (FTA1)
Abaft	A point beyond the midpoint of a ship's length. (MARAD2)
Abandoned Runway	Intact but not maintained or intended for use runway. (DOI3)
Abbreviated Injury Scale	An integer scale developed by the Association for the Advancement of Automotive Medicine to rate the severity of individual injuries. (NHTSA2)
Abbreviated Instrument Flight Rules (IFR) Flight Plans	An authorization by Air Traffic Control (ATC) requiring pilots to submit only that information needed for the purpose of ATC. It includes only a small portion of the usual Instrument Flight Rules (IFR) flight plan information. In certain instances, this may be only aircraft identification, location, and pilot request. Other information may be requested if needed by ATC for separation/control purposes. It is frequently used by aircraft which are airborne and desire an instrument approach or by aircraft which are on the ground and desire a climb to Visual Flight Rule (VFR)-on-top. (FAA4)
Abeam	An aircraft is "abeam" a fix, point, or object when that fix, point, or object is approximately 90 degrees to the right or left of the aircraft track. Abeam indicates a general position rather than a precise point. (FAA4)
Abort	To terminate a preplanned aircraft maneuver; (e.g., an aborted takeoff). (FAA4)
Absolute Block	A block in which no train is permitted to enter while it is occupied by another train. (49CFR218)
Accelerate Stop Distance Available	The runway plus stopway length declared available and suitable for the acceleration and deceleration of an airplane aborting a takeoff. (FAA4) (FAA12)
Acceleration Power	Measured in kilowatts. Pulse power obtainable from a battery used to accelerate a vehicle. This is based on a constant current pulse for 30 seconds at no less than 2/3 of the maximum open-circuit-voltage, at 80% depth-of-discharge relative to the battery's rated capacity and at 20 degrees Celsius ambient temperature. (DOE6)
Access Restrictions Road Gate	Constraints on use. (DOI3)
Access Rights	This element identifies who has acquired legal access rights over a road segment. (DOI2)
Accessible Stations	A public transportation passenger facility which provides ready access, is useable, and does not have physical barriers that prohibit and/or restrict access by individuals with disabilities, including individuals who use wheelchairs. (FTA1)
Accessible Vehicles	Public transportation revenue vehicles which do not restrict access, are usable, and provide allocated space and/or priority seating for individuals who use wheelchairs. (FTA1)
Accessory or Auxiliary Equipment	A particular item of equipment added to a vehicle to aid or contribute to the vehicle's operation and/or mission. (GSA2)
Accident	An incident involving a moving vehicle. Includes collisions with a vehicle, object, or person (except suicides) and derailment/left roadway. (FTA2) Occurrence in a sequence of events that produces unintended injury, death or property damage. Accident refers to the event, not the result of the event. (NSC1)
Accident (Aircraft)	As defined by the National Transportation Safety Board, an occurrence incidental to flight in which, as a result of the operation of an aircraft, any person (occupant or nonoccupant) receives fatal or serious injury or any aircraft receives substantial damage.
Accident (Automobile)	An event that produces injury and/or property damage, involves a motor vehicle in transport, and occurs on a trafficway or while the vehicle is still in motion after running off the trafficway.
Accident (Gas)	1) An event that involves the release of gas from a pipeline or of liquefied natural gas (LNG) or other gas from an LNG facility resulting in personal injury necessitating in-patient hospitalization or a death; or estimated property damage of $50,000 or more to the operator or others, or both, including the value of the gas that escaped during the accident; 2) an event that results in an emergency shutdown of an LNG facility; or 3) an event that is significant in the judgment of the operator even though it did not meet the criteria of (1) or (2).
Accident (Hazardous Liquid Or Gas)	Release of hazardous liquid or carbon dioxide while being transported, resulting in any of the following 1) an explosion or fire not intentionally set by the operator; 2) loss of 50 or more barrels of hazardous liquid or carbon dioxide; 3) release to the atmosphere of more than 5 barrels a day of highly volatile liquids; 4) death of any person; 5) bodily harm resulting in one or more of the following—a) the loss of consciousness, b) the necessity of carrying a person from the scene, c) the necessity for medical treatment, d) disability that prevents the discharge of normal duties, and 6) estimated damage to the property of the operators and/or others exceeding $50,000.
Accident (Highway-Rail Grade-Crossing)	An impact between on-track railroad equipment and an automobile, bus, truck, motorcycle, bicycle, farm vehicle, or pedestrian or other highway user at a designated crossing site. Sidewalks, pathways, shoulders, and ditches associated with the crossing are considered to be part of the crossing site.
Accident (Rail)	A collision, derailment, fire, explosion, act of God, or other event involving operation of railroad on-track equipment (standing or moving) that results in railroad damage exceeding an established dollar threshold.
Accident (Recreational Boating)	An occurrence involving a vessel or its equipment that results in 1) a death; 2) an injury that requires medical treatment beyond first aid; 3) damage to a vessel and other property, totaling more than $500 or resulting in the complete loss of a vessel; or 4) the disappearance of the vessel under circumstances that indicate death or injury. Federal regulations (33 CFR 173–4) require the operator of any vessel that is numbered or used for recreational purposes to submit an accident report.
Accident (Transit)	An incident involving a moving vehicle, including another vehicle, an object, or person (except suicides), or a derailment/left roadway.
Accident Classes	Used to categorize commercial vehicle accidents according to accident severity (i.e., fatal accidents, injury accidents, and property damage accidents). (FHWA4)
Accident Consequences	The physical results of motor vehicle accidents. Consequences include fatalities, injuries, and property damage. (FHWA2) (FHWA4)
Accident Severity	Measures the seriousness of an accident according to the type and quantity of the accident's consequences. Fatalities are more severe than injuries, and injuries are more severe than property damage. (FHWA2) (FHWA4)
Accident Type	An accident type is classified as either "collision" or "non-collision." (FHWA2) (FHWA4)
Accident/Incident	1) Any impact between railroad on-track equipment and an automobile, bus, truck, motorcycle, bicycle, farm vehicle or pedestrian at a rail-highway grade crossing; 2) Any collision, derailment, fire, explosion, act of God, or other event involving operation of railroad on-track equipment (standing or moving) that results in more than $6,300 in damages to railroad on-track equipment, signals, track, track structures, and road-bed; 3) Any event arising from the operation of a railroad which results in i) Death of one or more persons; ii) Injury to one or more persons, other than railroad employees, that requires medical treatment; iii) Injury to one or more employees that requires medical treatment or results in restriction of work or motion for one or more days, one or more lost work days, transfer to another job, termination of employment, or loss of consciousness; or iv) Occupational illness of a railroad employee as diagnosed by a physician. (49CFR225)
Accounting Changes Income (Loss)	The difference between the amount of retained earnings at the beginning of the period in which a change in accounting has occurred and the amount of retained earnings that would have been reported, net of applicable taxes, at that date if the new accounting had been applied retroactively for all applicable periods. (BTS4)
Acknowledging Device	A manually operated electric switch or pneumatic valve by means of which, on a locomotive equipped with an automatic train stop or train control device, an automatic brake application can be forestalled, or by means of which, on a locomotive equipped with an automatic cab signal device, the sounding of the cab indicator can be silenced. (49CFR236)
Acknowledging Time	As applied to an intermittent automatic train stop system, a predetermined time within which an automatic brake application may be forestalled by means of the acknowledging device. (49CFR236)
Acknowledgment Circuit	A circuit consisting of wire or other conducting material installed between the track rails at each signal in territory where an automatic train stop system or cab signal system of the continuous inductive type with 2-indication cab signals is in service, to enforce acknowledgement by the engineman at each signal displaying an aspect requiring a stop. (49CFR236)
Acrobatic Flight	An intentional maneuver involving an abrupt change in an aircraft's attitude, an abnormal attitude, or abnormal acceleration not necessary for normal flight. (FAA4)
Active Aircraft	All legally registered civil aircraft which flew one or more hours. (FAA2) (FAA6) (FAA9)
Active Vehicle	Transit passenger vehicles licensed, where required, and maintained for regular use, including spares and vehicles out of service for maintenance purposes, but excluding vehicles in "dead" storage, leased to other operators, in energy contingency reserve status, permanently not usable for transit service, and new vehicles not yet outfitted for active service. (APTA1)
Active Vehicles in Fleet	The vehicles in the year end fleet that are available to operate in revenue service, including vehicles temporarily out of service for routine maintenance and minor repairs. (FTA1)
Actual Calculated Landing Time (ACLT)	A flight's frozen calculated landing time. An actual time determined at freeze calculated landing time (FCLT) or meter list display interval (MLDI) for the adapted vertex for each arrival aircraft based upon runway configuration, airport acceptance rate, airport arrival delay period, and other metered arrival aircraft. This time is either the vertex time of arrival (VTA) of the aircraft or the tentative calculated landing time (TCLT)/actual calculated landing time (ACLT) of the previous aircraft plus the arrival aircraft interval (AAI), whichever is later. This time will not be updated in response to the aircraft's progress. (FAA4)
Actual Service	Total service operated during each time period. Actual service excludes missed trips and service interruptions (e.g., strikes, emergency shutdowns), but includes deadheading. Actual service is measured by vehicles in service, in miles and/or hours. (FTA1)
Actual Severity	On scene evaluation of the degree of danger that existed. An "after-the-fact" evaluation by the reporting unit. (USCG3)
Actual Vehicle Miles/Hours	The miles/hours a vehicle travels while in revenue service (actual vehicle revenue miles/hours) plus deadhead miles/hours. For rail vehicles, vehicle miles/hours refer to passenger car miles/hours. Actual vehicle miles/hours exclude miles and hours for charter services, school bus service, operator training and maintenance testing. (FTA1)
Ad Valorem	1) A freight rate set at a certain percentage of the value of an article; 2) A set percentage of the value of dutiable goods determined by the price at the port of shipment and calculated for duty assessment. (TNDOT1)
Additional Capital Invested	The difference between the price at which capital stock is sold and the par or stated value of the stock, gains or losses arising from the reacquisition and the resale or retirement of each class and series of capital stock, donations, the excess of retained earnings capitalized over par or stated value of capital stock issued, adjustments in capital resulting from reorganization or recapitalization, proceeds attributable to detachable stock purchase warrants related to debt issues, and contributions to the business enterprise by individual proprietors or partners. (BTS4)
Additional Services	Advisory information provided by Air Traffic Control (ATC) which includes but is not limited to the following 1) Traffic advisories. 2) Vectors, when requested by the pilot, to assist aircraft receiving traffic advisories to avoid observed traffic. 3) Altitude deviation information of 300 feet or more from an assigned altitude as observed on a verified (reading
Additional Vehicle	A vehicle added to the inventory of a Fleet Management Center to fill a new program or to expand on an existing program of a participating agency. (GSA2)
Adjustable Speed Drives	Drives that save energy by ensuring the motor's speed is properly matched to the load placed on the motor. Terms used to describe this category include polyphase motors, motor oversizing, and motor rewinding. (DOE5)
Administrative Class V Road	An administrative access road which consists of all public roads intended for access to administrative developments or structures such as offices, employee quarters, or utility areas. (DOI1)
Administrative Class VI Road	A restricted road normally closed to the public, including patrol roads, truck trails, and other similar roads. (DOI1)
Administrative Road	Consists of all public and non-public roads intended to be used principally for administrative purposes. It includes roads servicing employee residential areas, maintenance areas and other administrative developments, as well as restricted patrol roads, truck trails, and similar service roads. (DOI1)
Advances from Associated Companies	Net amounts due associated companies and nontransport divisions for notes, loans and advances that are not settled currently. (BTS4)
Adverse Weather	The weather conditions considered by the operator in identifying the response systems and equipment to be deployed in accordance with a response plan, including wave height, ice, temperature, visibility, and currents within the inland or Coastal Response Zone (defined in the National Contingency Plan (40 CFR 300)) in which those systems or equipment are intended to function. (49CFR194)
Advise Intentions	Tell me what you plan to do. (FAA4)
Advising Bank	A domestic bank which handles letters of credit for a foreign bank by notifying the exporter that the credit has been opened in his favor, fully informing him of the conditions and terms without responsibility on the part of the bank. (TNDOT1)
Advisory Frequency	The appropriate frequency to be used for Airport Advisory Service. (FAA4)
Advisory Service	Advice and information provided by a facility to assist pilots in the safe conduct of flight and aircraft movement. (FAA4)
Aerial Application	Any use of an aircraft for work purposes which concerns the production of foods, fibers, and health control in which the aircraft is used in lieu of farm implements or ground vehicles for the particular task accomplished. This includes fire fighting operations, the distribution of chemicals or seeds in agriculture, reforestation, or insect control. (FAA2) (FAA9)
Aerial Application Flying	The operation of aircraft for the purpose of dispensing any substance for plant nourishment, soil treatment, propagation of plant life, pest control, or fire control, including flying to and from the application site. (NTSB2)
Aerial Observation	Any use of an aircraft for aerial mapping and photography, survey, patrol, fish spotting, search and rescue, hunting, highway traffic advisory, or sightseeing; not included under Part 135. (FAA2) (FAA9)
Aerial Refueling	A procedure used by the military to transfer fuel from one aircraft to another during flight. (FAA4)
Aerial Tramway	An electric system of aerial cables with suspended unpowered passenger vehicles. The vehicles are propelled by separate cables attached to the vehicle suspension system and powered by engines or motors at a central location not on board the vehicle. (APTA1)
Aerodrome	(See also Airport, Heliport) A defined area on land or water (including any buildings, installations, and equipment) intended to be used either wholly or in part for the arrival, departure, and movement of aircraft. Aerodromes may include airports, heliports, and other landing areas. (FAA4) (FAA8)
Aerodrome Beacon	Aeronautical beacon used to indicate the location of an aerodrome from the air. (FAA4)
Aerodrome Control Tower	A unit established to provide air traffic control service to aerodrome traffic. (FAA4)
Aerodrome Elevation	The elevation of the highest point of the landing area. (FAA4)
Aerodrome Traffic Circuit	The specified path to be flown by aircraft operating in the vicinity of an aerodrome. (FAA4)
Aerodynamic Coefficient	Non-dimensional coefficients for aerodynamic forces and moments. (14CFR1)
Aeronautical Beacon	A visual Navigation Aid (NAVAID) displaying flashes of white and/or colored light to indicate the location of an airport, a heliport, a landmark, a certain point of a federal airway in mountainous terrain, or an obstruction. (FAA4)
Aeronautical Chart	A map used in air navigation containing all or part of the following topographic features hazards and obstructions, navigation aids, navigation routes, designated airspace, and airports. (FAA4)
Aeronautical Information Manual (AIM)	A primary Federal Aviation Administration (FAA) publication whose purpose is to instruct airmen about operating in the National Airspace System of the U.S. It provides basic flight information, Air Traffic Control (ATC) procedures and general instructional information concerning health, medical facts, factors affecting flight safety, accident and hazard reporting, and types of aeronautical charts and their use. (FAA4)
Aeronautics	Science that treats of the operation of aircraft, also the art or science of operating aircraft. (AIA1)
Aggregate Ratio	See Estimate Ratio, Mean and Ratio Estimate.
Agitator Body	Truck body designed and equipped to mix concrete in transit. (ATA1)
Agricultural Commodity Trailer	A trailer that is designed to transport bulk agricultural commodities in off-road harvesting sites and to a processing plant or storage location, as evidenced by skeletal construction that accommodates harvest containers, a maximum length of 28 feet, and an arrangement of air control lines and reservoirs that minimizes damage in field operations. (49CFR393)
Air Brake	A brake in which the mechanism is actuated by manipulation of air pressure. The term is often used to describe brakes that employ air under pressure above atmospheric, in contrast to vacuum brakes, which employ pressure below atmospheric. (TRB1)
Air Cargo	Total volume of freight, mail and express traffic transported by air. Includes the following Freight and Express-commodities of all kinds, includes small package counter services, express services and priority reserved freight; U.S. Mail-all classes of mail transported for the U.S. Postal Service. (ATAB1)
Air Carrier	The commercial system of air transportation comprising large certificated air carriers, small certificated air carriers, commuter air carriers, on-demand air taxis, supplemental air carriers, and air travel clubs.
Air Carrier Activity Information System (ACAIS)	Database of revenue passenger enplanement and all-cargo landing data used in the distribution of AIP (Airport Improvement Program) entitlement funds. (FAA11)
Air Carrier Operations	Arrivals and departures of air carriers certificated in accordance with Federal Aviation Regulations (FAR) Parts 121 and 127. (FAA14)
Air Commerce	Interstate, overseas, or foreign air commerce or the transportation of mail by aircraft or any operation or navigation of aircraft within the limits of any Federal airway or any operation or navigation of aircraft which directly affects, or which may endanger safety in, interstate, overseas, or foreign air commerce. (14CFR1)
Air Courier Service	Establishments primarily engaged in furnishing air delivery of individually addressed letters, parcels, and packages (generally under 100 pounds), except by the U.S. Postal service. While these establishments deliver letters, parcels, and packages by air, the initial pick-up and the final delivery are often made by other modes of transportation, such as by truck, bicycle, or motorcycle. Separate establishments of air courier companies engaged in providing pick-up and delivery only, drop-off points; or distribution centers are all classified in this industry. (BOC1)
Air Defense Identification Zone (ADIZ)	The area of airspace over land or water, extending upward from the surface, within which the ready identification, location, and control of aircraft are required in the interest of national security. Air Defense Identification Zone (ADIZ) locations and operating and flight plan requirements for civil aircraft operations are specified in FAR Part 99. (FAA4)
Air Express (Reserved Priority Air Freight)	Freight shipments which are shipped on a guaranteed served flight basis at a premium rate, not to be confused with small package service which is restricted to shipments of 50 pounds or less. (BTS5)
Air Mode	See Aviation Mode.
Air Navigation Facility	(See also Navigational Aid) Any facility used in, available for use in, or designed for use in, aid of air navigation, including landing areas, lights, any apparatus or equipment for disseminating weather information, for signaling, for radio-directional finding, or for radio or other electrical communication, and any other structure or mechanism having a similar purpose for guiding or controlling flight in the air or the landing and take-off of aircraft. (FAA4)
Air Navigation Hazard	An object which, as a result of an aeronautical study, the Federal Aviation Administration (FAA) determines will have an adverse effect upon the safe and efficient use of navigable airspace by aircraft, operation of air navigation facilities, or existing or potential airport capacity. (FAA12)
Air Operator	A person or organization authorized to operate aircraft or aviation facilities under FAR Parts 91, 121, 125, 127, 129, 133, 135, or 137. (FAA3)
Air Quality Conformity	The link between air quality planning and transportation planning
Air Route Surveillance Radar (ARSR)	Air Route Traffic Control Center (ARTCC) radar used primarily to detect and display an aircraft's position while en route between terminal areas. The ARSR enables controllers to provide radar air traffic control service when aircraft are within the ARSR coverage. In some instances, ARSR may enable an Air Route Traffic Control Center (ARTCC) to provide terminal radar services similar to but usually more limited than those provided by a radar approach control. (FAA4)
Air Route Traffic Control Center (ARTCC)	A facility established to provide air traffic control service to aircraft operating on an Instrument Flight Rules (IFR) flight plan within controlled airspace and principally during the en route phase of flight. When equipment capabilities and controller workload permit, certain advisory and assistance services may be provided to Visual Flight Rules (VFR) aircraft. (FAA2) (FAA13) (FAA14)
Air Taxi	An aircraft operator who conducts operations for hire or compensation in accordance with 14 CFR 135 (for safety purposes) or FAR Part 135 (for economic regulations or reporting purposes) in an aircraft with 30 or fewer passenger seats and a payload capacity of 7,500 pounds or less. An air taxi operates on an on-demand basis and does not meet the flight schedule qualifications of a commuter air carrier (see below).
Air Taxi Survey	Federal Aviation Administration (FAA) form 1800-31, sent to carriers for reporting of Air Taxi Commercial Operator (ATCO) activity. (FAA11)
Air Taxi/Commercial Operator (ATCO)	Commercial air carrier operating on-demand air taxi services on aircraft. Certificated in accordance with Federal Aviation Regulation Part 135. (FAA11)
Air Traffic	Aircraft operating in the air or on an airport surface, exclusive of loading ramps and parking areas. Also referred to as airport traffic. (14CFR1) (FAA4) (FAA14)
Air Traffic Clearance	An authorization by air traffic control, for the purpose of preventing collision between known aircraft, for an aircraft to proceed under specified traffic conditions within controlled airspace. (14CFR1) (FAA4)
Air Traffic Command and Control Center (ATCCC)	An Air Traffic Operations service facility consisting of four operational units; 1) Central Flow Control Function (CFCF)-Responsible for coordination and approval of all major inter-center flow control restrictions on a system basis in order to obtain maximum utilization of the airspace. 2) Responsible for coordinating, planning,and approving special user requirements under the Altitude Reservation concept. 3) Airport Reservation Office (ARO)-Responsible for approving Instrument Flight Rules (IFR) flights at designated high density traffic airports (John F. Kennedy, LaGuardia, O'Hare and Washington National) during specified hours. 4) Air Traffic Control (ATC) Contingency Command Post-A facility that enables the Federal Aviation Administration (FAA) to manage the ATC system when a significant portion of the system's capabilities have been lost or are threatened. (FAA8)
Air Traffic Control (ATC)	Service operated by an appropriate authority to promote the safe, orderly, and expeditious flow of air traffic. (FAA2)
Air Traffic Control (ATC) Clearance	Authorization for an aircraft to proceed under conditions specified by an air traffic control unit. (FAA4)
Air Traffic Control Facility	A facility which provides air traffic control services located in the U.S., its possessions and territories, and in foreign countries especially established by international agreement. (FAA2)
Air Traffic Control Service	A service provided for the purpose of 1) Preventing collisions between aircraft and on the maneuvering area between aircraft and obstructions and 2) Expediting and maintaining an orderly flow of air traffic. (FAA4)
Air Traffic Control Specialist	(See also Controller; Final Controller) A person authorized to provide air traffic control service. (FAA4)
Air Traffic Hub	Air traffic hubs are not airports; they are the cities and Standard Metropolitan Statistical Areas requiring aviation services. The hubs fall into four classes as determined by each community's percentage of the total enplaned passengers all services and all operations U.S. certificated air carriers in the 50 states, the District of Columbia, and other U.S. areas designated by the Federal Aviation Administration. Large a community enplaning 1.00% or more of the total enplaned passengers; Medium 0.25% to 0.99%; Small 0.05% to 0.24%; Nonhub Less than 0.05%. (FAA2) (FAA10) (FAA13) (FAA14) (FAA15)
Air Traffic Liabilities	The value of transportation sold, but not used or refunded (i.e., liabilities to passengers or liabilities to others. These include payables to other airlines for portions of interline passenger trips amounts the ticketing carrier owes the performing carrier. Also included are amounts the ticketing carrier owes to passengers prior to flights, which remain unearned revenue until air transportation is provided). (BTS4)
Air Traffic Management (ATM)	The process used to ensure the safe, efficient, and expeditious movement of aircraft during all phases of operations. Air traffic management consists of air traffic control and traffic flow management. (FAA7)
Air Traffic Service	A generic term meaning: 1) Flight Information Service; 2) Alerting Service; 3) Air Traffic Advisory Service; 4) Air Traffic Control Service, Area Control Service, Approach Control Service, or Airport Control Service. (FAA4)
Air Transport Movements	Landing and take-off of an aircraft operating a scheduled or non-scheduled service. (ACI1)
Air Transportation	Includes establishments that provide domestic and international passenger and freight services, and establishments that operate airports and provide terminal facilities. Also included are flying services such as crop dusting and aerial photography. (BEA1)
Air Travel Club	An operator certificated in accordance with FAR Part 123 to engage in the carriage of members who qualify for that carriage by payment of an assessment, dues, membership fees, or other similar remittance. (FAA14)
Air Waybill	A bill of lading which covers both domestic and international flights transporting goods to a specified destination. Technically, it is a non-negotiable instrument of air transport which serves as a receipt for the shipper, indicating that the carrier has accepted the goods listed therein and obligates itself to carry the consignment to the airport of destination according to specified conditions. (USTTA1)
Airbus Industries Group (AIG)	A supernational management organization responsible for design, development, manufacture, marketing, sales and support of selected commercial aircraft. (USTTA1)
Aircraft	See also Airframe, Airplane, Airship.
Aircraft Accident	Occurrence incident to flight in which, "as a result of the operation of an aircraft, any person (occupant or nonoccupant) receives fatal or serious injury or any aircraft receives substantial damage." The definition of substantial damage is 1) substantial damage means damage or failure which adversely affects the structural strength, performance, or flight characteristics of the aircraft, and would normally require major repair or replacement of the affected component; 2) engine failure, damage limited to an engine, bent fairings or cowling, dented skin, small punctured holes in the skin or fabric, ground damage to rotor or propeller blades, damage to landing gear, wheels, tires, flaps, engine accessories, brakes, or wingtips are not considered "substantial damage." (NTSB1)
Aircraft Agreement (Agreement On Trade In Civil Aircraft)	Negotiated in the Tokyo Round of the Multilateral Trade Negotiations, and implemented January 1, 1980, providing for elimination of tariff and non-tariff trade barriers in the civil aircraft sector. (AIA1)
Aircraft and Traffic Servicing Expenses	Compensation of ground personnel, in-flight expenses for handling and protecting all nonpassenger traffic including passenger baggage, and other expenses incurred on the ground to 1) Protect and control the in-flight movement of aircraft, 2) Schedule and prepare aircraft operational crews for flight assignment, 3) Handle and service aircraft while in line operation, and 4) Service and handle traffic on the ground after issuance of documents establishing the air carrier's responsibility to provide air transportation. (BTS4)
Aircraft Approach Category	A grouping of aircraft based on 1.3 times their stall speed in landing configuration at maximum certified landing weight. (FAA12)
Aircraft Approach Category A	Speed less than 91 knots. (FAA12)
Aircraft Approach Category B	Speed 91 knots or more but less than 121 knots. (FAA12)
Aircraft Approach Category C	Speed 121 knots or more but less than 141 knots. (FAA12)
Aircraft Approach Category D	Speed 141 knots or more but less than 166 knots. (FAA12)
Aircraft Approach Category E	Speed 166 knots or more. (FAA12)
Aircraft Contact	Aircraft with which the Flight Service Stations (FSS) have established radio communications contact. One count is made for each en route, landing, or departing aircraft contacted by an FSS regardless of the number of contacts made with an individual aircraft during the same flight. A flight contacting five FSS's would be counted as five aircraft contacted. (FAA2) (FAA13) (FAA14)
Aircraft Departure	An aircraft takeoff made at an airport. (FAA15)
Aircraft Engine	An engine that is used or intended to be used for propelling aircraft. It includes turbosuperchargers, appurtenances, and accessories necessary for its functioning, but does not include propellers. (14CFR1)
Aircraft Facility	(See also Airport; Heliport) An area where aircraft can take-off and land, usually equipped with associated buildings and facilities. (DOI3)
Aircraft Incident	An occurrence, other than an accident, associated with the operation of an aircraft that affects or could affect the safety of operations and that is investigated and reported on FAA Form 8020-5. (FAA3)
Aircraft Industry	Industry primarily engaged in the manufacture of aircraft, aircraft engines and parts including propellers and auxiliary equipment. (AIA1)
Aircraft Miles Scheduled	The sum of the airport-to-airport distances of all flights scheduled, excluding those operated only as extra sections to accommodate traffic overflow. (BTS5)
Aircraft Operations	The airborne movement of aircraft in controlled or non controlled airport terminal areas, and counts at en route fixes or other points where counts can be made. (FAA14)
Aircraft Revenue Departures Performed	The number of aircraft take-offs actually performed in scheduled passenger/cargo and all-cargo services. (BTS5) (BTS6)
Aircraft Revenue Hours	The airborne hours in revenue service, computed from the moment an aircraft leaves the ground until it touches the ground again. (BTS5) (BTS6)
Aircraft Revenue Mile	The miles (computed in airport-to-airport distances) for each inter-airport hop actually completed in revenue service, whether or not performed in accordance with the scheduled pattern. For this purpose, operation to a flag stop is a hop completed even though a landing is not actually made. In cases where the inter-airport distances are inapplicable, aircraft miles flown are determined by multiplying the normal cruising speed for the aircraft type by the airborne hours. (BTS5) (BTS6)
Aircraft Type	A distinctive model of an aircraft as designated by the manufacturer. (FAA15)
Aircraft-Miles	The distance flown by aircraft in terms of great circle airport-to-airport distances measured in statute miles. (NTSB1)
Airframe	Structural components of an airplane, such as fuselage, empennage, wings, landing gear, and engine mounts, but excluding such items as engines, accessories, electronics, and other parts that may be replaced from time to time. (AIA1)
Airline Transport Pilot	An airline transport pilot may act as a pilot-in-command of an aircraft engaged in air carrier service. (FAA2)
Airman	A pilot, mechanic or other licensed aviation technician. (FAA2)
Airman Certificate	A document issued by the Administrator of the Federal Aviation Administration certifying that the holder complies with the regulations governing the capacity in which the certificate authorizes the holder to act as an airman in connection with aircraft. (FAA2)
Airman's Meteorological Information (AIRMET)	In-flight weather advisories issued only to amend the area forecast concerning weather phenomena which are of operational interest to all aircraft and potentially hazardous to aircraft having limited capability because of lack of equipment, instrumentation, or pilot qualifications. Airman's Meteorological Information's (AIRMET) concern weather of less severity than that covered by Significant Meteorological Convective Information's (SIGMET) or Convective SIGMET's. AIRMET's cover moderate icing, moderate turbulence, sustained winds of 30 knots or more at the surface, widespread areas of ceilings less than 1,000 feet and/or visibility less than 3 miles, and extensive mountain obscurement. (FAA4)
Airplane	An engine-driven lighter-than-air aircraft that can be steered. (14CFR1)
Airplane Design Group	A grouping of airplanes based on wingspan. (FAA12)
Airplane Design Group I	A wingspan up to but not including 49 feet (15 m). (FAA12)
Airplane Design Group II	A wingspan 49 feet (15m) up to but not including 79 feet (24 m). (FAA12)
Airplane Design Group III	A wingspan 79 feet (24m) up to but not including 118 feet (36 m). (FAA12)
Airplane Design Group IV	A wingspan 118 feet (36m) up to but not including 171 feet (52 m). (FAA12)
Airplane Design Group V	A wingspan 171 feet (52m) up to but not including 214 feet (65 m). (FAA12)
Airplane Design Group VI	A wingspan 214 feet (65 m) up to but not including 262 feet (80 m). (FAA12)
Airport	A landing area regularly used by aircraft for receiving or discharging passengers or cargo.
Airport Acceptance Rate (AAR)	A dynamic input parameter specifying the number of arriving aircraft which an airport or airspace can accept from the Air Route Traffic Control Center per hour. The AAR is used to calculate the desired interval between successive arrival aircraft. (FAA4)
Airport Advisory Area	The area within ten miles of an airport without a control tower or where the tower is not in operation, and on which a Flight Service Station is located. (FAA4)
Airport Advisory Service	A service provided by flight service stations at airports not served by a control tower. This service consists of providing information to arriving and departing aircraft concerning wind direction/speed-favored runway, altimeter setting, pertinent known traffic/field conditions, airport taxi routes/traffic patterns, and authorized instrument approach procedures. This information is advisory in nature and does not constitute an Air Traffic Control (ATC) clearance. (FAA2) (FAA13) (FAA14)
Airport and Airways Trust Fund	Mechanism for funding capital improvements for the nation's air traffic control system and airports. The fund is supported by taxes contributed by users of the aviation system, including an 10 percent tax of airline passengers and a tax on aviation fuel. Established by the Airport and Airway Revenue Act of 1970. (FAA11)
Airport Elevation	The highest point on an airport's usable runways expressed in feet above mean sea level. (FAA4) (FAA12)
Airport Improvement Program (AIP)	Provides funding from the Airport and Airway Trust Fund for airport development, airport planning, noise compatibility planning, and to carry out noise compatibility programs.(FAA11)
Airport Information Desk	An airport unmanned facility designed for pilot self-service briefing, flight planning, and filing of flight plans. (FAA4)
Airport Layout Plan (ALP)	The plan of an airport showing the layout of existing and proposed airport facilities. (FAA12)
Airport Lighting	Various lighting aids that may be installed on an airport. (FAA4)
Airport Lighting (Runway Lights/Runway Edge Lights)	Lights having a prescribed angle of emission used to define the lateral limits of a runway. Runway lights are uniformly spaced at intervals of approximately 200 feet, and the intensity may be controlled or preset. (FAA4)
Airport Marking Aids	Markings used on runway and taxiway surfaces to identify a specific runway, a runway threshold, a centerline, a hold line, etc. A runway should be marked in accordance with its present usage such as 1) Visual. 2) Nonprecision instrument. 3) Precision instrument. (FAA4)
Airport Operations	The number of arrivals and departures from the airport at which the airport traffic control tower is located. There are two types of operations local and itinerant. (FAA13)
Airport Reference Dataset (AIRE)	Regenerated annually from data provided by National Flight Data Center (NFDC). (FAA11)
Airport Reference Point (ARP)	The latitude and longitude of the approximate center of the airport. (FAA12)
Airport Reservation Office (ARO)	Office responsible for monitoring the operation of the high density rule. Receives and processes requests for Instrument Flight Rules (IFR) operations at high density traffic airports. (FAA4)
Airport Runway Centerline Lighting	Flush centerline lights spaced at 60-foot intervals beginning 76 feet from the landing threshold and extending to within 75 feet of the opposite end of the runway. (FAA4)
Airport Runway End Identifier Lighting (REIL)	Two synchronized flashing lights, one on each side of the runway threshold, which provide rapid and positive identification of the approach end of a particular runway. (FAA4)
Airport Surface Detection Equipment (ASDE)	Radar equipment specifically designed to detect all principal features on the surface of an airport, including aircraft and vehicular traffic, and to present the entire image on a radar indicator console in the control tower. Used to augment visual observation by tower personnel of aircraft and/or vehicular movements on runways and taxiways. (FAA4)
Airport Surveillance Radar (ASR)	(See also Ground Controlled Approach, Precision Approach Radar) Approach control radar used to detect and display an aircraft's position in the terminal area. Airport Surveillance Radar (ASR) provides range and azimuth information but does not provide elevation data. Coverage of the ASR can extend up to 60 miles. (FAA4)
Airport Taxi Charts	Designed to expedite the efficient and safe flow of ground traffic at an airport. These are identified by the official airport name (e.g, Washington National Airport). (FAA4)
Airport Threshold Lighting	Fixed green lights arranged symmetrically left and right of the runway centerline, identifying the runway threshold. (FAA4)
Airport Touchdown Zone Lighting	Two rows of transverse light bars located symmetrically about the runway centerline normally at 100 foot intervals. The basic system extends 3,000 feet along the runway. (FAA4)
Airport Traffic	Aircraft operating in the air or on an airport surface exclusive of loading ramps and parking areas. (FAA2)
Airport Traffic Control Service	Air traffic control service provided by an airport traffic control tower for aircraft operating on the movement area and in the vicinity of an airport. (FAA2)
Airport Traffic Control Tower (ATCT)	A central operations facility in the terminal air traffic control system, which consists of a tower cab structure, including an associated IFR room if radar equipped, and uses air/ground communications, radar, visual signaling, and other services to provide safe and expeditious movement of terminal air traffic. (FAA2)
Airport Visual Approach Slope Indicator Lighting (VASI)	An airport lighting facility providing vertical visual approach slope guidance to aircraft during approach to landing by radiating a directional pattern of high intensity red and white focused light beams which indicate to the pilot that he is "on path" if he sees red/white, "above path" if white/white, and "below path " if red/red. Some airports serving large aircraft have three-bar Visual Approach Slope Indicators (VASI) which provide two visual glide paths to the same runway. (FAA4)
Airport/Facility Directory	A publication designed primarily as a pilot's operational manual containing all airports, seaplane bases, and heliports open to the public including communications data, navigational facilities, and certain special notices and procedures. This publication is issued in seven volumes according to geographical area. (FAA4)
Airports Grants In Aid Program	A grant of funds by the Secretary of Transportation under the Airport & Airway Improvement Act of 1982 to a sponsor for the accomplishment of one or more projects. (FAA2)
Airports of Entry	Aircraft may land at these airports without prior permission to land from U.S. Customs. (FAA2)
Airports, Flying Fields, and Airport Terminal Services	Establishments primarily engaged in operating and maintaining airports and flying fields, in servicing, repairing (except on a factory basis), maintaining and storing aircraft; and in furnishing coordinated handling services for airfreight or passengers at airports. This industry also includes private establishments primarily engaged in air traffic control operations. (BOC1)
Airship	An engine-driven fixed-wing aircraft heavier than air, that is supported in flight by the dynamic reaction of the air against its wings. (14CFR1)
Airspace Hierarchy	Within the airspace classes, there is a hierarchy and, in the event of an overlap of airspace Class A preempts Class B. Class B preempts Class C, Class C preempts Class D, Class D preempts Class E. and Class E preempts Class G. (FAA4)
Airspeed	The speed of an aircraft relative to its surrounding air mass. The unqualified term "airspeed", means one of the following. 1) Indicated Airspeed. The speed shown on the aircraft airspeed indicator. This is the speed used in pilot/controller communications under the general term "airspeed." 2) True Airspeed. The airspeed of an aircraft relative to undisturbed air. Used primarily in flight planning and en route portion of flight. When used in pilot/controller communications, it is referred to as "true airspeed" and not shortened to "airspeed." (FAA4)
Airstart	The starting of an aircraft engine while the aircraft is airborne, preceded by engine shutdown during training flights or by actual engine failure. (FAA4)
Airway	A Class E airspace area established in the form of a corridor, the centerline of which is defined by radio navigational aids. (FAA4)
Airway Beacon	Used to mark airway segments in remote mountain areas. The light flashes Morse Code to identify the beacon site. (FAA4)
Alcohol Concentration (AC)	The concentration of alcohol in a person's blood or breath. When expressed as a percentage it means grams of alcohol per 100 milliliters of blood or grams of alcohol per 210 liters of breath. (49CFR383)
Alcohol Involvement	A fatality or fatal crash as alcohol-related or alcohol involved if 1) Either a driver or a nonmotorist (usually a pedestrian) had a measurable or estimated blood alcohol concentration (BAC) of 0.01 grams per deciliter (g/dl) or above. Probabilities of alcohol involvement are now calculated for each driver, pedestrian, or crash. 2) Coded by police when evidence of alcohol is present. This code does not necessarily mean that a driver, passenger or nonoccupant was tested for alcohol. (NHTSA1) (NHTSA3)
Alert Notice	A request originated by a Flight Service Station (FSS) or an air route traffic control center (ARTCC) for an extensive communication search for overdue, unreported, or missing aircraft. Also known as Alnot. (FAA4)
Alerting Service	A service provided to notify appropriate organizations regarding aircraft in need of search and rescue aid and assist such organizations as required. (FAA4)
All Clear	Term used in boating to mean 1) That a tow boat is ready to leave barge or 2) Is clear of an obstruction. (TNDOT1)
All Services	The total of scheduled and nonscheduled transport services. (BTS4) (BTS5) (FAA15)
All-Cargo and Mail Aircraft	Movements by aircraft and helicopters operated for commercial transport operations involving freight and/or mail, but not passengers. (ACI1)
All-Cargo Carrier	An air carrier certificated in accordance with Federal Aviation Regulations (FAR) Part 121 to provide scheduled air freight, express,and mail transportation over specified routes, as well as to conduct nonscheduled operations that may include passengers. (FAA14)
Allocation	An administrative distribution of funds for programs that do not have statutory distribution formulas.
Allowance For Depreciation	Asset valuation account which includes the balance of the offsetting credit to be capitalized asset value-to represent the loss and deterioration in value of the asset over time, so that the asset is amortized over its useful life, and provisions are made for replacement of the asset at the end of its productive life. (BTS4)
Allowance For Uncollectable Accounts	Accruals for estimated losses from uncollectible accounts. (BTS4)
Alluvial Stream	Any stream whose banks are subject to attack, allowing channel meander. The stream has the property of depositing material such as soil, sand, or gravel and building up land in one area while washing it away in another. (TNDOT1)
Alnot	See Alert Notice.
Alongside	The side of the ship. Goods to be delivered "alongside" are to be placed on the dock or lighter within reach of the ship's tackle so that they can be loaded aboard the ship. (TNDOT1)
Alphanumeric Display	Letters and numerals used to show identification (ID), altitude, beacon code, and other information concerning a target on a radar display. (FAA4)
Alternate Airport	An airport at which an aircraft may land if a landing at the intended airport becomes inadvisable. (14CFR1)
Alternative Fuel Capacity	The on-site availability of apparatus to burn fuels other than natural gas. (DOE1)
Alternative Fuels	The Energy Policy Act of 1992 defines alternative fuels as methanol, denatured ethanol, and other alcohol; mixtures containing 85 percent or more (but not less than 70 percent as determined by the Secretary of Energy by rule to provide for requirements relating to cold start, safety, or vehicle functions) by volume of methanol, denatured ethanol, and other alcohols with gasoline or other fuels. Includes compressed natural gas, liquid petroleum gas, hydrogen, coal-derived liquid fuels, fuels other than alcohols derived from biological materials, electricity, or any other fuel the Secretary of Energy determines by rule is substantially not petroleum and would yield substantial energy security and environmental benefits.
Altimeter Setting	The barometric pressure reading used to adjust a pressure altimeter for variations in existing atmospheric pressure or to the standard altimeter setting (29.92). (FAA4)
Altitude	The vertical distance of a level, a point or an object considered as a point measured in feet Above Ground Level (AGL) or from Mean Sea Level (MSL). 1) MSL Altitude. Altitude expressed in feet measured from mean sea level. 2) AGL Altitude. Altitude expressed in feet measured above ground level. 3) Indicated Altitude. The altitude as shown by an altimeter. On a pressure or barometric altimeter it is altitude as shown uncorrected for instrument error and uncompensated for variation from standard atmospheric conditions. (FAA4)
Altitude Encoding	An aircraft altitude transmitted via the Mode C transponder feature that is visually displayed in 100 feet increments on the ground radar scope having readout capability. (FAA6)
Altitude Engine	A reciprocating aircraft engine having a rated takeoff power that is producible from sea level to an established higher altitude. (14CFR1)
Altitude Readout	An aircraft's altitude, transmitted via the Mode C transponder feature, that is visually displayed in 100-foot increments on a radar scope having readout capability. (FAA4)
Altitude Reservation (ALTRV)	(See also Formation Flight) Airspace utilization under prescribed conditions normally employed for the mass movement of aircraft or other special requirements which cannot otherwise be accomplished. ALTRVs are approved by the appropriate Federal Aviation Administration (FAA) facility. (FAA4) (FAA8)
Altitude Restriction	An altitude or altitudes, stated in the order flown, which are to be maintained until reaching a specific point or time. Altitude restrictions may be issued by Air Traffic Control (ATC) due to traffic, terrain, or other airspace considerations. (FAA4) (FAA8)
Altitude Restrictions Are Canceled	Adherence to previously imposed altitude restrictions is no longer required during a climb or descent. (FAA4)
Ambulance or Rescue Service	Establishments primarily engaged in furnishing ambulances or rescue services, except by air, where such operations are primarily within a single municipality, contiguous municipalities, or a single municipality and its suburban areas. (BOC1)
American Association of State Highway & Transportation Officials (AASHTO)	A nonprofit, nonpartisan association representing highway and transportation departments in the 50 states, the District of Columbia and Puerto Rico. It represents all five transportation modes: air, highways, public transportation, rail and water. Its primary goal is to foster the development, operation and maintenance of an integrated national transportation system.
American Institute of Certified Planners (AICP)	The American Planning Association's professional institute that provides recognized leadership nationwide in the certification of professional planners, ethics, professional development, planning education, and the standards of planning practice.
American Planning Association (APA)	A nonprofit public interest and research organization committed to urban, suburban, regional, and rural planning. APA and its professional institute, the American Institute of Certified Planners, advance the art and science of planning to meet the needs of people and society.
American Public Transportation Association (APTA)	Acting as a leading force in advancing public transportation, APTA serves and leads its diverse membership through advocacy, innovation, and information sharing to strengthen and expand public transportation.
Americans With Disabilities Act (ADA)	The legislation defining the responsibilities of and requirements for transportation providers to make transportation accessible to individuals with disabilities. (FTA1)
Amortization of Developmental and Preoperating Expenses, Etc.	Charges to expense for the 1) Amortization of capitalized developmental and preoperating cost and other intangible assets; and 2) Obsolescence and deterioration of flight equipment spare parts (included under depreciation and amortization). (BTS4)
Amortization, Capital Leases	Charges applicable to assets recorded under capital leases. (BTS4)
Amtrak	Operated by the National Railroad Passenger Corporation, this rail system was created by the Rail Passenger Service Act of 1970 (Public Law 91-518, 84 Stat. 1327) and given the responsibility for the operation of intercity, as distinct from suburban, passenger trains between points designated by the Secretary of Transportation.
An Easy Distance Off	A reasonably close (comfortable) distance off the bank, allowing ample room for maneuverability. This is a relative term depending upon size of stream and size of tow. The term "easy" pertains more to ease of mind than to closeness of distance and indicates that this portion of the river has no tight spots. (TNDOT1)
Analysis of Alternatives	Understanding how the transportation system and its components work such as information on the costs, benefits and impacts of potential chances to the system.
Anchor It	Apply brakes for an emergency stop. (ATA1)
Anchorage	An area where a vessel anchors or may anchor, either because of suitability or designation. (DOI3)
Angle Collision	Collisions which are not head on, rear end, rear to rear, or sideswipe. (NHTSA3)
Annual Funding Agreement	A negotiated annual written funding agreement between a Self-Governance Indian Tribal Government (ITG) and the Secretary of the Interior, authorizing the ITG to plan, conduct, consolidate, and administer programs, services, functions, and activities or portions thereof previously administered by the Department of the Interior through the BIA, and other programs for which appropriations are made available for the ITG through the Secretary of the Interior from agencies other than Department of the Interior (DOI).
Annual Operating Factor	The annual fuel consumption divided by the product of design firing rate and hours of operation per year. (DOE5)
Antenna	A metallic apparatus for sending and receiving electromagnetic waves. (DOI4)
Antenna Array	A group of directional antennas. (DOI4)
Appliance	Any instrument, mechanism, equipment, part, apparatus, appurtenance or accessory, including communications equipment, that is used or intended to be used in operating or controlling an aircraft in flight, is installed in or attached to the aircraft, and is not part of an airframe, engine, or propeller. (14CFR1)
Applicant	A governmental entity, a non-profit public-purpose organization, or any responsible person having the legal, financial, and technical capacity to implement an intermodal passenger terminal project under 49 CFR 256. The applicant must have legal authority to receive and expend Federal funds. (49CFR256)
Apportionment	1) A term that refers to a statutorily prescribed division or assignment of funds. An apportionment is based on prescribed formulas in the law and consists of dividing authorized obligation authority for a specific program among the States. 2) The distribution of funds as prescribed by a statutory formula.
Approach Clearance	Authorization by Air Traffic Control (ATC) for a pilot to conduct an instrument approach. The type of instrument approach for which a clearance and other pertinent information is provided in the approach clearance when required. (FAA4)
Approach Control Facility	A terminal air traffic control facility providing approach control service. (FAA2) (FAA4) (FAA13) (FAA14)
Approach Control Service	Air traffic control service provided by an approach control facility for arriving and departing Visual Flight Rules (VFR)/Instrument Flight Rule (IFR) aircraft and, on occasion, en route aircraft. At some airports not served by an approach control facility, the Air Route Traffic Control Center (ARTCC) provides limited approach control service. (FAA2) (FAA4) (FAA13) (FAA14)
Approach Gate	An imaginary point used within Air Traffic Control (ATC) as a basis for vectoring aircraft to the final approach course. The gate will be established along the final approach course 1 mile from the outer marker (or the fix used in lieu of the outer marker) on the side away from the airport for precision approaches and 1 mile from the final approach fix on the side away from the airport for nonprecision approaches. In either case when measured along the final approach course, the gate will be no closer than 6 miles from the landing threshold. (FAA4)
Approach Light System (ALS)	An airport lighting facility which provides visual guidance to landing aircraft by radiating light beams in a directional pattern by which the pilot aligns the aircraft with the extended centerline of the runway on his final approach for landing. Condenser-Discharge Sequential Flashing Lights/Sequenced Flashing Lights may be installed in conjunction with the Approach Lighting System (ALS) at some airports. Types of Approach Light Systems are 1) (ALSF-1) Approach Light System with Sequenced Flashing Lights in Instrument Landing System (ILS) Cat-I configuration. 2) (ALSF-2) Approach Light System with Sequenced Flashing Lights in ILS Cat-II configuration. The ALSF-2 may operate as a Simplified Short Approach Light System with Runway Alignment Indicator Lights (SSALR) when weather conditions permit. 3) Simplified Short Approach Light System with Sequenced Flashing Lights (SSALF). 4) Simplified Short Approach Light System with Runway Alignment Indicator Lights (SSALR). 5) (MALSF) Medium Intensity Approach Light System with Sequenced Flashing Lights. 6) Medium Intensity Approach Light System with Runway Alignment Indicator Lights (MALSR). 7) Lead-in-light system (LDIN) Consists of one or more series of flashing lights installed at or near ground level that provides positive visual guidance along an approach path, either curving or straight, where special problems exist with hazardous terrain, obstructions, or noise aba
Approach Locking	Electric locking effective while a train is approaching, within a specified distance, a signal displaying an aspect to proceed, and which prevents, until after the expiration of a predetermined time interval after such signal has been caused to display its most restrictive aspect, the movement of any interlocked or electrically locked switch, movable-point frog, or derail in the route governed by the signal, and which prevents an aspect to proceed from being displayed for any conflicting route. (49CFR236)
Approach Sequence	The order in which aircraft are positioned while on approach or awaiting approach clearance. (FAA4)
Approach Signal	A roadway signal used to govern the approach to another signal and if operative so controlled that its indication furnishes advance information of the indication of the next signal. (49CFR236)
Approach Speed	The recommended speed contained in aircraft manuals used by pilots when making an approach to landing. This speed will vary for different segments of an approach as well as for aircraft weight and configuration. (FAA4)
Approachway	The airspace through which aircraft approach or leave a landing area. (DOI4)
Appropriate Air Traffic Service (ATS) Authority	The relevant authority designated by the State responsible for providing air traffic services (ATS) in the airspace concerned. In the United States, the "appropriate ATS authority" is the Director, Office of Air Traffic System Management, ATM-1. (FAA4)
Appropriate Authority	1) Regarding flight over the high seas the relevant authority is the State of Registry. 2) Regarding flight over other than the high seas the relevant authority is the State having sovereignty over the territory being overflown. (FAA4)
Appropriated Budget Authority (ABA)	A form of Budget Authority that requires both an authorization act and an appropriations act before any funds can be obligated.
Appropriation	Authorization of funding expenditures from Congress.
Appropriations Act	Action of a legislative body that makes funds available for expenditure with specific limitations as to amount, purpose, and duration. In most cases, it permits money previously authorized to be obligated and payments made, but for the highway program operating under contract authority, the appropriations act specifies amounts of funds that Congress will make available for the fiscal year to liquidate obligations.
Approved	A term used to indicate Coast Guard approval of a specific item among the limited number that the Coast Guard has been directed by law to test and "approve." Some of these items are personal flotation devices, fire extinguishers, carburetor backfire flame arresters, distress signals, and certain types of life rafts. The standards program has not required "approval" of any boat or item of associated equipment. (USCG1)
Apron	1) A floor or lining-of resistant material at the toe of a dam or bottom of a spillway to prevent erosion from turbulent water flow; 2) That portion of a pier and wharf measured between the outer edges of the water-facing side and the transit shed or other inshore structure. (TNDOT1)
Aqueduct	(See also Canal/Ditch) A structure designed to transport domestic or industrial water from a supply source to a distribution point, often by gravity. (DOI3)
Arch	A curved structure that supports the weight of material over an open space. (DOI4)
Area Control Center	An International Civil Aviation Organization (ICAO) term for an air traffic control facility primarily responsible for Air Traffic Control (ATC) services being provided Instrument Flight Rules (IFR) aircraft during the en route phase of flight. The U.S. equivalent facility is an air route traffic control center. (FAA4)
Area Control Computer Complex (ACCC)	The common automation system equipment and software that support control of aircraft in a specific area, and which is located within each area control facility. The Area Control Computer Complex (ACCC) is one portion of the AAS (Advanced Automation System). (FAA8)
Area Control Facility (ACF)	[As of 1992] The planned 23 facilities that result from consolidation of existing Air Route Traffic Control Center (ARTCC) and Terminal Radar Approach Control (TRACON)/Terminal Radar Approach Control in Tower Cab (TRACAB) facilities. An Area Control Facility (ACF) may be formed from an existing ARTCC or may be created in a new building. The number, location, and implementation dates of ACFs are in accordance with the National Airspace System Plan. There will be 20 Continental U.S. (CONUS) ACFs converted from ARTCCs; plus Honolulu, Anchorage, and the New York TRACON. Each can accomplish an en route and approach/departure control. (FAA8)
Area Navigation (RNAV)	A method of navigation that permits aircraft operation on any desired course within the coverage of station-referenced navigation signals or within the limits of a self-contained system capability. Random area navigation routes are direct routes, based on area navigation capability, between waypoints defined in terms of latitude/longitude coordinates, degree/distance fixes, or offsets from published or established routes/airways at a specified distance and direction. The major types of equipment are 1) Combined VOR and TACAN navigational facility (VORTAC) referenced or Course Line Computer (CLC) systems, which account for the greatest number of Radio Navigation (RNAV) units in use. To function, the CLC must be within the service range of a VORTAC. 2
Area Source	Small stationary and non-transportation pollution sources that are too small and/or numerous to be included as point sources but may collectively contribute significantly to air pollution (e.g., dry cleaners).
Area to Be Submerged	The known extent of the intended lake that will be created behind a dam under construction. (DOI3)
Area Wide Template	A computerized format (spreadsheet) for data entry of system length, vehicle travel, population, net land area, fatal and injury accidents, and percent of travel by vehicle type. (FHWA2)
Areawide Control Schedule	An accounting and project management tool that is developed from tribal Transportation Improvement Programs, tribal control schedules, and tribal priority lists to identify detailed project information for the expenditure of IRR funds for the current and next four fiscal years.
Arising from the Operation of a Railroad	Includes all activities of a railroad which are related to the performance of its rail transportation business. (49CFR225)
Armed Forces	The Army, Navy, Air Force, Marine Corps, and Coast Guard, including their regular and reserve components and members serving without component status. (14CFR1)
Armstrong Starter	Old-fashioned hand crank. (ATA1)
Army Aviation Flight Information Bulletin	A bulletin that provides air operation data covering Army, National Guard, and Army Reserve aviation activities. (FAA4)
Arrangement of Passenger Transportation	Includes establishments engaged in providing travel information and acting as agents in arranging tours, transportation, car rentals, and lodging for travelers. (BEA1)
Arrangement of Passenger Transportation Not Elsewhere Classified	Establishments primarily engaged in arranging passenger transportation (other than travel agencies and tour operators), such as ticket offices (not operated by transportation companies) for railroads, buses, ships, and airlines. (BOC1)
Arresting System	A safety device consisting of two major components, name, engaging or catching devices and energy absorption devices for the purpose of arresting both tailhook and/or nontailhook-equipped aircraft. It is used to prevent aircraft from overrunning runways when the aircraft cannot be stopped after landing or during aborted takeoff. Arresting systems have various names; (e.g., arresting gear, hook device, wire barrier cable). (FAA4)
Arrival Aircraft Interval (AAI)	An internally generated program in hundredths of minutes based upon the Airport Acceptance Rate. Arrival Airport Interval is the desired optimum interval between successive arrival aircraft over the vertex. (FAA4)
Arrival Center	The air route traffic control center having jurisdiction for the impacted airport. (FAA4)
Arrival Delay	A parameter which specifies a period of time in which no aircraft will be metered for arrival at the specified airport. (FAA4)
Arrival Post	A signboard placed approximately 1/2 mile below the lock on the upstream and the downstream side to inform the pilot of the towboat that he has arrived at the lock and his preference is rated upon his first arrival either below or above. This term is falling into disuse since the advent of radio communications between towboats and the lock. (TNDOT1)
Arrival Program Sequencing	The automated program designed to assist in sequencing aircraft destined for the same airport. (FAA4)
Arrival Sector	An operational control sector containing one or more meter fixes. (FAA4)
Arrival Time	The time an aircraft touches down on arrival. (FAA4)
Arterial	A class of roads serving major traffic movements (high-speed, high volume) for travel between major points.
Arterial Highway	A major highway used primarily for through traffic.
Arterial Street	A class of street serving major traffic movements (high-speed, high volume) for travel between major points.
Articulated Bus	A bus usually 55 feet or more in length with two connected passenger compartments that bends at the connecting point when the bus turns a corner. (APTA1)
Articulated Motor Buses	Extra-long (54 ft. to 60 ft.) motor buses with the rear body section connected to the main body by a joint mechanism. The joint mechanism allows the vehicles to bend when in operation for sharp turns and curves, and yet have a continuous interior. (FTA1)
Aspect	The appearance of a roadway signal conveying an indication as viewed from the direction of an approaching train; the appearance of a cab signal conveying an indication as viewed by an observer in the cab. (49CFR236)
Asphalt	A dark brown to black cement-like material containing bitumen as the predominant constituent. The definition includes crude asphalt and finished products such as cements, fluxes, the asphalt content of emulsions, and petroleum distillates blended with asphalt to make cutback asphalt. Asphalt is obtained by petroleum processing.
Assigned Vehicle	A vehicle provided to an organizational element of a government agency or contractor by General Services Administration's (GSA) Interagency Fleet Management System for a period of more than 30 days. (GSA1)
Associated Equipment	Any system, part or component of a boat as originally manufactured or any similar part or component manufactured or sold for replacement, repair, or improvement of such system, part, or component; any accessory or equipment for, or appurtenance to, a boat; and any marine safety article, accessory, or equipment intended for use by a person on board a boat; but excluding radio equipment, as designated by the Secretary [of Transportation] under 46 U.S.C. 2101. (USCG1)
Association of Metropolitan Planning Organizations (AMPO)	AMPO is a nonprofit, membership organization established in 1994 to serve the needs and interests of "metropolitan planning organizations (MPOs)" nationwide. AMPO offers its member MPOs technical assistance and training, conferences and workshops, frequent print and electronic communications, research, a forum for transportation policy development and coalition building, and a variety of other services.
Astern	1) Behind a vessel; 2) Move in a reverse direction. (MARAD2)
Astronautics	Art and science of designing, building, and operating manned or unmanned space objects. (AIA1)
At Anchor	Held in place in the water by an anchor. Includes "moored" to a buoy or anchored vessel and "dragging anchor". (USCG2)
At Grade	See also Grade Crossings, Highway-Rail Crossing.
At Grade, Exclusive Right-of-Way	Railway right-of-way from which all other traffic, mixed and cross, is excluded. Median strip right-of-way is included provided all crossings of the right-of-way pass over or under the median. (FTA1)
At Grade, Mixed and Cross Traffic	Railway right-of-way over which other traffic moving in the same direction or the cross directions may pass. City street right-of-way is included. (FTA1)
At Grade, with Cross Traffic	Railway right-of-way over which no other traffic may pass, except to cross at grade-level crossings. A median strip right-of-way with grade-level crossings at intersecting streets is included. (FTA1)
Attainment Area	An area considered to have air quality that meets or exceeds the U.S. Environmental Protection Agency (EPA) health standards used in the Clean Air Act. Nonattainment areas are areas considered not to have met these standards for designated pollutants. An area may be an attainment area for one pollutant and a nonattainment area for others.
Audit	Periodic investigation of financial statements and their relationships to planned or permitted expenditures.
Authorization	Basic substantive legislation or that which empowers an agency to implement a particular program and also establishes an upper limit on the amount of funds that can be appropriated for that program
Authorization Act	Basic substantive legislation that establishes or continues Federal programs or agencies and establishes an upper limit on the amount of funds for the program(s). The current authorization act for surface transportation programs is the Transportation Equity Act for the 21st Century (TEA-21).
Authorized Altitude	A published altitude representing the maximum usable altitude or flight level for an airspace structure or route segment. It is the highest altitude on a federal airway, jet route, area navigation low or high route, or other direct route for which a Minimum En Route Instrument Flight Rules (IFR) Altitude (MEA) is designated in Part 95 at which adequate reception of navigation aid signals is assured. (FAA4)
Auto inspection and maintenance (IM)	Programs require the testing of motor vehicles in parts of the country with unhealthy air and the repair of those that do not meet standards.
Auto Restricted Zone	An area in which normal automobile traffic is prohibited or limited to certain times, and vehicular traffic is restricted to public transit, emergency vehicles, taxicabs and, in some cases, delivery of goods. (APTA1)
Autoland Approach	(See also Coupled Approach) A precision instrument approach to touchdown and, in some cases, through the landing rollout. An autoland approach is performed by the aircraft autopilot which is receiving position information and/or steering commands from onboard navigation equipment. (FAA4)
Automated Flight Service Station	A station that provides interactive alphanumeric and graphic work stations for the flight service specialist. (FAA8)
Automated Guideway	An electric railway operating without vehicle operators or other crew on board the vehicle. (APTA1)
Automated Guideway Transit	Guided transit vehicles operating singly or in multi-car trains with a fully automated system (no crew on transit units). Service may be on a fixed schedule or in response to a passenger-activated call button. Automated guideway transit includes personal rapid transit, group rapid transit and people mover systems. (FTA1)
Automated Guideway Transit System	Fixed-guideway transit system which operates with automated (driverless) individual vehicles or multi-car trains. Service may be on a fixed schedule or in response to a passenger-activated call button. (49CFR137)
Automated Guideway Vehicles	Guided transit passenger vehicles operating under a fully automated system (no crew on transit units). (FTA1)
Automated Mutual Assistance Vessel Rescue System (AMVER)	A facility which can deliver, in a matter of minutes, a Surface Picture (SURPIC) of vessels in the area of a potential or actual search and rescue incident, including their predicted positions and their characteristics. (FAA4)
Automated Radar Terminal System (ARTS)	The generic term for the ultimate in functional capability afforded by several automation systems. Each differs in functional capabilities and equipment. Automated Radar Terminal System (ARTS) plus a suffix roman numeral denotes a specific system. A foll
Automated Radar Terminal Type IIIA System (ARTS IIIA)	The Radar Tracking and Beacon Tracking Level (RT&BTL) of the modular, programmable automated radar terminal system. Automated Radar Terminal System (ARTS) IIIA detects, tracks, and predicts primary as well as secondary radar-derived aircraft targets. This more sophisticated computer-driven system upgrades the existing ARTS III system by providing improved tracking, continuous data recording, and fail-safe capabilities. (FAA4)
Automated Radar Tracking System	An automated radar and radar beacon tracking system. Its functional capabilities and design are essentially the same as the terminal Automated Radar Terminal System (ARTS) IIIA system except for the En Route Automated Radar Systems (EARTS) capability of employing both short-range Airport Surveillance Radar (ASR) and long-range Air Route Surveillance Radar (ARSR) radars, use of full digital radar displays, and fail-safe design. (FAA4)
Automated Transfer Information	A precoordinated process, specifically defined in facility directives, during which a transfer of altitude control and/or radar identification is accomplished without verbal coordination between controllers using information communicated in a full data block. (FAA4)
Automatic Altitude Reporting	That function of a transponder which responds to Mode C interrogations by transmitting the aircraft's altitude in 100-foot increments. (FAA4)
Automatic Block Sign System	A block signal system wherein the use of each block is governed by an automatic block signal, cab signal, or both. (49CFR236)
Automatic Carrier Landing System	U.S. Navy final approach equipment consisting of precision tracking radar coupled to a computer data link to provide continuous information to the aircraft, monitoring capability to the pilot, and a backup approach system. (FAA4)
Automatic Direction Finder (ADF)	An aircraft radio navigation system which senses and indicates the direction to a Low/Medium Frequency (L/MF) nondirectional radio beacon (NDB) ground transmitter. Direction is indicated to the pilot as a magnetic bearing or as a relative bearing to the longitudinal axis of the aircraft depending on the type of indicator installed in the aircraft. In certain applications, such as military, ADF operations may be based on airborne and ground transmitters in the VHF/UHF frequency spectrum. (FAA4) (FAA6)
Automatic Fare Collection (AFC) System	The controls and equipment that automatically admit passengers on insertion of the correct fare in an acceptable form, which may be coins, tokens, tickets, or farecards (stored value farecards must be inserted again on exit, at which point an additional fare may be required). (TRB1)
Automatic Interlocking	An arrangement of signals, with or without other signal appliances, which functions through the exercise of inherent powers as distinguished from those whose functions are controlled manually, and which are so interconnected by means of electric circuits that their movements must succeed each other in proper sequence, train movements over all routes being governed by signal indication. (49CFR236)
Automatic Pilot	The roll, pitch, and yaw axis of an aircraft can be controlled by use of an automatic pilot. Information from very high frequency omni-directional radio range (VOR), instrument landing systems (ILS), microwave landing systems (MLS), and other navigation aids can be coupled to the automatic pilot for en route and approach flights. (FAA6) (FAA10)
Automatic Restraint System	Any restraint system that requires no action on the part of the driver or passengers to be effective in providing occupant crash protection (e.g., air bags or passive belts). (NHTSA1)
Automatic Terminal Information Service	The continuous broadcast of recorded noncontrol information in selected terminal areas. Its purpose is to improve controller effectiveness and to relieve frequency congestion by automating the repetitive transmission of essential but routine information. (FAA4)
Automatic Train Control System	A system so arranged that its operation will automatically result in the following; 1) A full service application of the brakes which will continue either until the train is brought to a stop, or, under control of the engineman, its speed is reduced to a predetermined rate; 2) When operating under a speed restriction, an application of the brakes when the speed of the train exceeds the predetermined rate and which will continue until the speed is reduced to that rate. (49CFR236)
Automatic Train Stop System	A system so arranged that its operation will automatically result in the application of the brakes until the train has been brought to a stop. (49CFR236)
Automatic Vehicle Location System	A system that senses, at intervals, the location of vehicles carrying special electronic equipment that communicates a signal back to a central control facility. (TRB1)
Automatic Vehicle Monitoring System	A system in which electronic equipment on a vehicle sends signals back to a central control facility, locating the vehicle and providing other information about its operations or about its mechanical condition. (TRB1)
Automobile	A privately owned and/or operated licensed motorized vehicle including cars, jeeps and station wagons. Leased and rented cars are included if they are privately operated and not used for picking up passengers in return for fare. (FHWA3)
Automobile Size Classification	Automobile size classifications as established by the Environmental Protection Agency (EPA) Minicompact - less than 85 cubic feet of passenger and luggage volume; Subcompact - between 85 to 100 cubic feet of passenger and luggage volume; Compact - between 100 to 110 cubic feet of passenger and luggage volume; Midsize - between 110 to 120 cubic feet of passenger and luggage volume; Large - more than 120 cubic feet of passenger and luggage volume; Two seater - automobiles designed primarily to seat only two adults. Station wagons are included with the size class for the sedan of the same name. (DOE6)
Automobile Transporter Body	Truck body designed for the transportation of other vehicles. (ATA1)
Automotive Billing Module (AutoBill)	This module creates non-GSA customer billing tapes and General Services Administration (GSA) interfund transactions from billing records generated in the Transportation Interface and Reporting System (TIRES) and generates monthly accounting transaction information to send to the NEAR (National Electronic Accounting and Reporting) system. (GSA2)
Automotive Payment Module (AutoPay)	This module processes all maintenance and extended warranty vendor invoices entered into the Fleet Service Station (FSS) Fleet Management System by the Maintenance Control Centers and processes the rental authorization records for commercial rent-a-car rentals from the Fleet Management Center. (GSA2)
Autorotation	A rotorcraft flight condition in which the lifting rotor is driven entirely by action of the air when the rotorcraft is in motion. 1. Autorotative Landing/Touchdown Autorotation. Used by a pilot to indicate that he will be landing without applying power to the rotor. 2. Low Level Autorotation. Commences at an altitude well below the traffic pattern, usually below 100 feet AGL and is used primarily for tactical military training. 3. 180 degrees Autorotation. Initiated from a downwind heading and is commenced well inside the normal traffic pattern. "Go around" may not be possible during the latter part of this maneuver. (FAA4)
Auxiliary Lock	[with respect to rail operations] A smaller secondary lock adjacent to the main lock. (TNDOT1)
Auxiliary Rotor	A rotor that serves either to counteract the effect of the main rotor torque on a rotorcraft or to maneuver the rotorcraft about one or more of its three principal axes. (14CFR1)
Available Flight Stage Length	The average distance covered per aircraft hop in revenue services, from take-off to landing. Derived by dividing the total aircraft miles flown in revenue service by the number of aircraft revenue departures performed. (BTS6)
Available Seat Mile	One seat transported one mile. (ATAB1)
Available Seat Mile (ASM)	The aircraft miles flown in each inter-airport hop multiplied by the number of seats available on that hop for revenue passenger use. (BTS5) (BTS6) (FAA14)
Available Seat-Miles (Air Carrier)	The aircraft-miles flown in each interairport hop multiplied by the number of seats available on that hop for revenue passenger service.
Available Ton Mile	One ton of capacity (passengers and cargo) transported one mile. (ATAB1)
Available Ton Miles	The aircraft miles flown in each inter-airport hop multiplied by the capacity available (in tons) for that hop. (BTS6)
Available Tons Per Aircraft Mile	The average total passenger/cargo carrying capacity (tons) offered for sale per aircraft per aircraft mile, derived by dividing the overall available ton miles by the total aircraft miles flown in revenue service. (BTS6)
Average Annual Daily Traffic (AADT)	The total volume of traffic on a highway segment for one year, divided by the number of days in the year.
Average Annual Daily Truck Traffic (AADTT)	The total volume of truck traffic on a highway segment for one year, divided by the number of days in the year.
Average Fare Per Unlinked Passenger Trip	Passenger revenue divided by unlinked passenger trips. (APTA1)
Average Fleet Age	The cumulative years active revenue vehicles are in service divided by the sum of all active revenue vehicles. (FTA1)
Average Flight Stage Length	The average distance covered per aircraft hop in revenue services, from take-off to landing. Derived by dividing the total aircraft miles flown in revenue service by the number of aircraft revenue departures performed. (BTS6)
Average Haul	The average distance, in miles, one ton is carried. It is computed by dividing ton-miles by tons of freight originated.
Average Length of Haul	(See also Ton Mile) The average distance in miles one ton is carried. Computed by dividing total ton-miles by tons of freight originated. (AAR1)
Average Lifetime Mileage per Active Vehicle	The cumulative mileage for each active vehicle from the date of manufacture through the end of the fiscal year divided by the number of active vehicles. (FTA1)
Average Number of Available Seats Per Aircraft	Available seat-miles divided by the number of aircraft revenue miles in passenger service. (BTS5) (BTS6)
Average Passenger Trip Length (Bus/Rail)	Calculated by dividing revenue passenger-miles by the number of revenue passengers.
Average Road Width	The average width of the travelway. (DOI2)
Average Vehicle Fuel Consumption	A ratio estimate defined as total gallons of fuel consumed by all vehicles, divided by 1) The total number of vehicles (for average fuel consumption per vehicle) or 2) The total number of households (for average fuel consumption per household). (DOE4)
Average Vehicle Miles Traveled	A ratio estimate defined as total miles traveled by all vehicles, divided by 1) the total number of vehicles (for average miles traveled per vehicle); or 2) the total number of households (for average miles traveled per household). (DOE4)
Average Weekday	A representative weekday in the operation of the transit system computed as the mathematical average of several typical weekdays selected at random throughout the year. A typical weekday is one where there are no anomalies such as high ridership due to extra service added for a convention, or low ridership due to a snowstorm. Average Saturday and Sunday data, including holiday service, are determined the same way. (FTA1)
Aviation Gasoline	All special grades of gasoline for use in aviation reciprocating engines, as given in the American Society of Testing and Materials (ASTM) Specification D910. Includes all refinery products within the gasoline range that are to be marketed straight or in blends as aviation gasoline without further processing (any refinery operation except mechanical blending). Also included are finished components in the gasoline range which will be used for blending or compounding into aviation gasoline. (DOE6)
Aviation Gasoline (General Aviation)	All special grades of gasoline used in aviation reciprocating engines, as specified by American Society of Testing Materials Specification D910 and Military Specification MIL-G5572. Includes refinery products within the gasoline range marketed as or blended to constitute aviation gasoline.
Aviation Gasoline Blending Components	Naphthas that are used for blending or compounding into finished aviation gasoline (e.g., straight-run gasoline, alkylate, and reformate). Excludes oxygenates (alcohols and ethers), butane, and pentanes plus. (DOE3)
Aviation Mode	Consists of airways and airports; airplanes, helicopters, and other flying craft for carrying passengers and cargo. (BTS1) (BTS2)
Aviation Weather Service	A service provided by the National Weather Service (NWS) and Federal Aviation Administration (FAA) which collects and disseminates pertinent weather information for pilots, aircraft operators, and Air Traffic Control (ATC). Available aviation weather reports and forecasts are displayed at each NWS office and FAA Flight Service Station (FSS). (FAA4)
Aviator	Speeding driver. (ATA1)
Avionics	Communications, navigation, flight controls, and displays. (AIA1)
Azimuth	A magnetic bearing extending from a microwave landing system navigation facility. (FAA4)
Back Chute	An old channel no longer used that may be located behind an island adjacent to the present navigable channel. It is sometimes used during high water stages to navigate without having to buck the strong currents in the main channel. (TNDOT1)
Back 'Er Down	To stop headway of a tow. (TNDOT1)
Back Up	To kill headway; to flank or twist tow at foot of crossing or head of bend. (TNDOT1)
Backhaul	The return trip of a transportation vehicle (typically a truck). Empty backhauls increase transportation costs for shippers, carriers, and consumers.
Backing Line	A line used on a tow to keep barges from running ahead. (TNDOT1)
Backing Rudders	See Flanking Rudder.
Backwater	1) Water backed up by a tributary stream; 2) An area of calm water unaffected by the current of a stream. (DOI4) (TNDOT1)
Backwater Curve	The term applied to the profile of the water surface above a dam or other obstruction in a channel. This may also be stated as the effect on the natural water surface profile of either of two confluent streams upstream from their confluence due to flow conditions in the other stream. (TNDOT1)
Backyard Boatbuilder	Person that builds a boat for his own use and not for the purposes of sale. A backyard boatbuilder may subcontract all work. (USCG1)
Balance of Trade	The difference between a country's total imports and exports; if the exports exceed the imports, a "favorable" balance of trade exists. (TNDOT1)
Balanced Transportation	See Intermodalism (3).
Ballast	Material place on a track bed to hold the track in line and elevation and to distribute its load. Suitable material consists of hard particles (e.g., crushed rock, slag, gravel) that are stable, easily tamped, permeable, and resistant to plant growth. (TRB1)
Balloon	A lighter-than-air aircraft that is not engine driven. (14CFR1)
Balloon Freight	Lightweight freight. (ATA1)
Bar	A submerged or emerged mound, ridge, or succession of ridges of sand or other material extending across the bottom and which may obstruct navigation. (DOI4)
Bareback	Tractor without its semitrailer. (ATA1)
Barge	See also Boat, Tanker.
Barge Carriers	Ships designed to carry barges. Some are fitted to act as full container-ships and can carry a varying number of barges and containers at the same time. (MARAD2)
Barrel	(See also Gallon) A unit of volume equal to 42 U.S. gallons at 60 Degrees Fahrenheit. (49CFR194) (49CFR195) (DOE3)
Barrel (Oil)	A unit of volume equal to 42 U.S. gallons.
Base Period (Off-Peak Period)	In transit, the time of day during which vehicle requirements and schedules are not influenced by peak-period passenger volume demands (e.g., between morning and afternoon peak periods). At this time, transit riding is fairly constant and usually low to moderate in volume when compared with peak-period travel. (TRB1)
Basic Grant	The funds available to a State for carrying out an approved State Enforcement Plan (SEP), which include, but are not limited to 1) Recruiting and training of personnel, payment of salaries and fringe benefits, the acquisition and maintenance of equipment except those at fixed weigh scales for the purposes of weight enforcement, and reasonable overhead costs needed to operate the program; 2) Commencement and conduct of expanded systems of enforcement; 3) Establishment of an effective out-of-service and compliance enforcement system, and 4) Retraining and replacing staff and equipment. (49CFR350)
Basic Utility Stage I Airport	This type of airport serves 75 percent of the single-engine and small twin-engine airplanes used for personal and business purposes. Precision approach operations are not usually anticipated. This airport is designed for small airplanes in Airport Reference Code B-I. (FAA12)
Basic Utility Stage II Airport	This type of airport serves all the airplanes of stage I plus some small business and air taxi-type twin-engine airplanes. Precision approach operations are not usually anticipated.This airport is also designed for small airplanes in Aircraft Reference Code B-I. (FAA12)
Basin	See also Inundation Area.
Bastard Tow	A tow made up of uneven or dissimilar barges. (TNDOT1)
Batture	The land on either side of a river between the low water stage of the river and the top of a levee. (TNDOT1)
Bay/Inlet	A water area that is an opening of the sea/ocean into the land, or of an estuary, lake, or river into its shore. (DOI3)
Beacon	A fixed signal, mark, or light and associated facilities erected for the guidance of mariners or airplane pilots. (DOI4)
Beam	The width of a ship. (MARAD2)
Bean Hauler	A driver who transports fruits and vegetables. (ATA1)
Bear Trap	A section of movable dam with concrete piers in either side (generally about 100 feet wide) and provided with a gate which may be raised or lowered by compressed air. The bear trap serves as a type of safety valve. When the pool level maintained at the dam becomes too high, the bear trap is lowered to permit the excess water to run out. This pool control feature of movable wicket-type dams is found on the Ohio and Illinois rivers. The Bear trap will always be located on the opposite side of the river from the lock and is very dangerous to approach when open. (TNDOT1)
Bearing	(See also Course, Flight Path) The horizontal direction to or from any point, usually measured clockwise from true north, magnetic north, or some other reference point, through 360 degrees. (FAA8)
Bed-Load Movement	Solids which are transported along the riverbed as a semi suspended sediment. (TNDOT1)
Beginning Milepost	The continuous milepost notation to the nearest 0.01 mile that marks the beginning of any road or trail segment. (DOI2)
Belly Cargo	Air freight carried in the belly of passenger aircraft.
Below Minimums	Weather conditions below the minimums prescribed by regulation for the particular action involved; (e.g., landing minimums, takeoff minimums). (FAA4)
Bend	Curve in the river, analogous to a curve in a highway. (TNDOT1)
Berm	The sharp definitive edge of a dredged channel such as in a rock cut. (TNDOT1)
Berth	(See also Wharfage) 1) A specific segment of wharfage where a ship ties up alongside at a pier, quay, wharf, or other structure that provides a breasting surface for the vessel. Typically, this structure is a stationary extension of an improved shore and intended to facilitate the transfer of cargo or passengers. (MARAD1)
Beverage Semitrailer	A van-type, drop-frame semitrailer designed and used specifically for the transport and delivery of bottled or canned beverages which has side-only access for loading and unloading this commodity. (23CFR658)
BIA Area Certification Acceptance Plan	A plan prepared by a specific area office which delineates how it will meet certification acceptance requirements under 23 U.S.C., Section 117(a). {This section of law was deleted in the Transportation Equity Act for the 21st Century. CA is being replaced by Stewardship Agreements.}
BIA Atlas Map	A series of maps which depict the IRR/BIA road system by reservation and jurisdictions.
BIA Classification of Roads	An identification of specific roads or trails that take into account current and future traffic generators, and relationships to connecting or adjacent BIA, State, county, Federal, and/or local roads.
BIA Roads System	Those existing and proposed roads for which the BIA has or plans to obtain legal right(s)-of-way. This includes only roads for which the BIA has the primary responsibility to construct, improve, and maintain. Any additions or deletions to this system must be supported by resolution from the ITG.
BIA/FHWA Memorandum of Agreement	An agreement between the BIA and the FHWA which contains mutually agreeable roles and responsibilities for the administration of the IRR and Highway BridgeReplacement and Rehabilitation programs.
Bible	The "Golden Rule" safe driving book. (ATA1)
Bicycle	A vehicle having two tandem wheels, propelled solely by human power, upon which any person or persons may ride. (23CFR217)
Bicycle Lane (Bike Lane)	A portion of a roadway which has been designated by striping, signing and pavement markings for the preferential or exclusive use of bicyclists. (23CFR217)
Bicycle Path (Bike Path)	A bikeway physically separated from motorized vehicular traffic by an open space or barrier and either within the highway right-of-way or within an independent right-of-way. (23CFR217)
Bicycle Route (Bike Route)	A segment of a system of bikeways designated by the jurisdiction having authority with appropriate directional and information markers, with or without a specific bicycle route number. (23CFR217)
Bicycles	Includes bicycles of all speeds and sizes that do not have a motor. (FHWA3)
Big Hat	State Trooper. (ATA1)
Big Rigger	Arrogant driver, or one who will drive only long trailers. (ATA1)
Bight of a Bend	Deepest portion of a bend (not in depth of water); sharpest part of a curve. (TNDOT1)
Bikeway	1) Any road, path, or way which in some manner is specifically designated as being open to bicycle travel, regardless of whether such facilities are designated for the exclusive use of bicycles or are to be shared with other transportation modes. (23CFR217) 2) A facility designed to accommodate bicycle travel for recreational or commuting purposes. Bikeways are not necessarily separated facilities; they may be designed and operated to be shared with other travel modes.
Bilateral Trade Agreement	Commerce between two countries based on a reciprocal trade agreement which specifies the quantity of goods to be traded, the time limit of the agreement and that the balances due be remitted directly between the countries. (TNDOT1)
Bill of Lading	A document that establishes the terms of a contract between a shipper and a transportation company. It serves as a document of title, a contract of carriage and a receipt for goods. (MARAD2)
Billing	A transaction conducted by a carrier involving the determination of the proper rate and total charges for a shipment and the issuance of a freight bill. (MARAD1)
Binders	Brakes. (ATA1)
Birdyback	Intermodal transportation system using highway freight containers carried by aircraft. (ATA1)
Blanket Certificate (Authority)	Permission granted by the Federal Energy Regulatory Commission (FERC) for a certificate holder to engage in an activity (such as transportation service or sales) on a self implementing or prior notice basis, as appropriate, without case-by-case approval from FERC. (DOE1)
Blind Side	Right side of truck and trailer. (ATA1)
Blind Speed	The rate of departure or closing of a target relative to the radar antenna at which cancellation of the primary radar target by moving target indicator (MTI) circuits in the radar equipment causes a reduction or complete loss of signal. (FAA4)
Blind Spot	An area from which radio transmissions and/or radar echoes cannot be received. The term is also used to describe portions of the airport not visible from the control tower. (FAA4)
Blind Velocity	The radial velocity of a moving target such that the target is not seen on primary radars fitted with certain forms of fixed echo suppression. (FAA4)
Blind Zone	See Blind Spot.
Block	A length of track of defined limits, the use of which by trains is governed by block signals, cab signals, or both. (49CFR236)
Block Signal	A roadway signal operated either automatically or manually at the entrance to a block. (49CFR236)
Block Signal System	A method of governing the movement of trains into or within one or more blocks by block signals or cab signals. (49CFR236)
Block to Block Time	See Flight Time.
Blocked	Phraseology used to indicate that a radio transmission has been distorted or interrupted due to multiple simultaneous radio transmissions. (FAA4)
Blood Alcohol Concentration (BAC)	Is measured as a percentage by weight of alcohol in the blood (grams/deciliter). A positive BAC level (0.01 g/dl and higher) indicates that alcohol was consumed by the person tested. A BAC level of 0.10 g/dl or more indicates that the person was intoxicated. (NHTSA3)
Blood Alcohol Concentration (Highway)	A measurement of the percentage of alcohol in the blood by grams per deciliter.
Blow Him Down	To sound the danger signal in case of misunderstood passing signals, when the pilot on the other boat refuses to obey signals, or when just desiring to pass information. (TNDOT1)
Blue Signal	A clearly distinguishable blue flag or blue light by day and a blue light at night. When attached to the operating controls of a locomotive, it need not be lighted if the inside of the cab area of the locomotive is sufficiently lighted so as to make the blue signal clearly distinguishable. (49CFR218)
Bluff Bar	A sandbar having a sharp drop-off into deep water. Also called a "bluff reef." (TNDOT1)
Board of Commissioners	A legal body of 3 to 9 individuals having broad administrative authority over a river port's operation. This board is primarily concerned with the development and determination of policies of the port authority. (TNDOT1)
Boat	See also Barge, General Cargo Ship, Motorboat, Towboat, Tugboat, Vessel.
Boat Trailer	A trailer designed with cradle-type mountings to transport a boat and configured to permit launching of the boat from the rear of the trailer. (49CFR571)
Boat Transporters	Any vehicle combination designed and used specifically to transport assembled boats and boat hulls. Boats may be partially disassembled to facilitate transporting. (23CFR658)
Boating Safety Circular (BSC)	Published by COMDT (G-NAB) for free distribution to boat and equipment manufacturers, dealers, marinas, yacht clubs, OCMI personnel and other boating organizations. Information in the BSC concerns boating standards and boating safety in general. (USCG1)
Bodily Injury	Injury to the body, sickness, or disease including death resulting from any of these. (49CFR387)
Body	See also Chassis.
Body Type	Refers to the individual classifications of motor vehicles by their design structure based on definitions developed by the Society of Automotive Engineers. (NHTSA2)
Bogey	An assembly of two or more axles. (ATA1)
Bogie	A set of wheels built specifically as rear wheels under the container. (MARAD2)
Boil	Turbulence in the water caused by deep holes, ends of dikes, channel changes, or other submerged obstructions. Indicates a changing channel condition. A boil is easily detected by electronic depth sounders by rapidly changing depths appearing as waves on the tracing paper. (TNDOT1)
Boiler Deck	See Cabin Deck.
Bold Reef	A bluff reef which acts like a weir and is plainly visible for quite some distance. (TNDOT1)
Bold Right-Hand Reef	A sandbar or group of rocks which can be seen or detected by water turbulence, located on the right bank of the channel. (TNDOT1)
Boll Weevil	A novice truck driver. (ATA1)
Bolt Lock	[with respect to rail operations] A mechanical lock so arranged that if a switch, derail or movable-point frog is not in the proper position for a train movement, the signal governing that movement cannot display an aspect to proceed; and that will prevent a movement of the switch, derail or movable-point frog unless the signal displays its most restrictive aspect. (49CFR236)
Bonded Petroleum Imports	Petroleum imported and entered into Customs bonded storage. These imports are not included in the import statistics until they are 1) Withdrawn from storage free of duty for use as fuel for vessels and aircraft engaged in international trade; or 2) Withdrawn from storage with duty paid for domestic use. (DOE5)
Booking	Arrangements with steamship companies for the acceptance and carriage of freight. (TNDOT1)
Boom It Down	Tighten chains around freight. (ATA1)
Boomers	Binder devices used to tighten chains around cargo on flatbed trailers. (ATA1)
Border Cargo Selectivity (BCS)	An automated cargo selectivity system based on historical and other information. The system is designed to facilitate cargo processing and to improve Customs enforcement capabilities by providing targeting information to border locations. The system is used for the land-border environment. (USTTA1)
Bottleneck	A section of a highway or rail network that experiences operational problems such as congestion. Bottlenecks may result from factors such as reduced roadway width or steep freeway grades that can slow trucks.
Bottlers Body	Truck body designed for hauling cased, bottled beverages. (ATA1)
Bottom	The portion of the ground surface which lies below water. (DOI4)
Bottom Dumps	Trailer that unloads through bottom gates. (ATA1)
Bottom Shell	That portion of a tank car tank surface, excluding the head ends of the tank car tank, that lies within two feet, measured circumferentially, of the bottom longitudinal center line of the tank car tank. (49CFR171)
Boundary	A nonphysical line indicating the limit or extent of an area or territory. (DOI4)
Bow	The front of a vessel. (MARAD2)
Box	1) Semitrailer; 2) The transmission part of the tractor. (ATA1)
Boxcar	An enclosed railcar, typically 40 or more feet long, used for packaged freight and some bulk commodities.
Brake	An energy conversion mechanism used to stop, or hold a vehicle stationary. (49CFR393)
Brake Horsepower	The power delivered at the propeller shaft (main drive or main output) of an aircraft engine. (14CFR1)
Brake Pipe	A pipe running from the engineman's brake valve through the train, used for the transmission of air under pressure to charge and actuate the automatic brake equipment and charge the reservoirs of the electro-pneumatic brake equipment on each vehicle of the train. (49CFR236)
Brake Shoe	The nonrotating portion of a tread or disc brake assembly. The shoe is pressed against the tread, disc, or drum when the brake is applied. (TRB1)
Brake Tubing/Hose	Metallic brake tubing, nonmetallic brake tubing and brake hose are conduits or lines used in a brake system to transmit or contain the medium (fluid or vacuum) used to apply the motor vehicle's brakes. (49CFR393)
Braking Action	A report of conditions on the airport movement area providing a pilot with a degree/quality of braking that he might expect. Braking action is reported in terms of good, fair, poor, or nil. (FAA4)
Braking Action Advisories	When tower controllers have received runway braking action reports which include the terms "poor" or "nil," or whenever weather conditions are conducive to deteriorating or rapidly changing runway braking conditions, the tower will include on the Automated Terminal Information Service (ATIS) broadcast the statement, "BRAKING ACTION ADVISORIES ARE IN EFFECT." During the time Braking Action Advisories are in effect, Air Traffic Control (ATC) will issue the latest braking action report for the runway in use to each arriving and departing aircraft. Pilots should be prepared for deteriorating braking conditions and should request current runway condition information if not volunteered by controllers. Pilots should also be prepared to provide a descriptive runway condition report to controllers after landing. (FAA4)
Break	A fracture resulting in complete separation into parts. (49CFR229)
Break the Unit	Uncouple the tractor from the trailer. (ATA1)
Break Up Tow	To disassemble the tow either at the end of the voyage or inadvertently on a sandbar. (TNDOT1)
Break-Bulk	Packages of hazardous materials that are handled individually, palletized, or unitized for purposes of transportation as opposed to bulk and containerized freight. (49CFR171)
Breakbulk Cargo	Cargo of non-uniform sizes, often transported on pallets, sacks, drums, or bags. These cargoes require labor-intensive loading and unloading processes. Examples of breakbulk cargo include coffee beans, logs, or pulp.
Breakdown Bar	A length of pipe used to increase the leverage in setting up ratchets when connecting tow rigging. Also called "cheater". (TNDOT1)
Breakout Tank	A tank used to 1) relieve surges in an oil or hazardous liquid pipeline system; or 2) receive and store oil or hazardous liquid transported by a pipeline for reinjection and continued transportation by pipeline. (49CFR194) (49CFR195)
Breakwater	A structure built to break the force of waves so as to protect a beach, harbor, or other waterfront facility. (DOI4)
Breast Line	Any line that leads straight in or square. Keeps a barge from moving out from its mooring facilities. (TNDOT1)
Bridge	A structure including supports erected over a depression or an obstruction, such as water, highway, or railway, and having a track or passageway for carrying traffic or other moving loads, and having an opening measured along the center of the roadway of more than 20 feet between undercopings of abutments or spring lines of arches, or extreme ends of openings for multiple boxes; it may also include multiple pipes, where the clear distance between openings is less than half of the smaller contiguous opening. (23CFR650)
Bridge Foundation Bearing Material	The type of material supporting the substructure of a bridge. Code as follows GW-well graded gravel, GP-poorly graded gravel, GM-silty gravel, GC-clay gravel, SW-well graded sand, SP-poorly graded sand, SM-silty sand, SC-clay sand, RK-bedrock, UK-unknown, O-other. (DOI2)
Bridge Management System (BMS)	A systematic process that provides, analyzes, and summarizes bridge information for use in selecting and implementing cost-effective bridge construction, rehabilitation, and maintenance programs
Bridge Number	The number of the installation, consisting of the full route number (including segment and spur) plus the milepost location of the bridge to the nearest one hundredth of a mile. (DOI2)
Bridge Posted Load Restrictions	Load restrictions posted at a bridge structure. Entry order single axle, dual axle, load type 3, load type 3S2, load type 3-3 and Special. (DOI2)
Bridge Posted Speed Restrictions	A speed limit posted at a bridge structure, in miles per hour. (DOI2)
Bridge Structure	A two character code for recording the type of bridge structure. Code as follows SS-simple span, CS-continuous span, SC-combination simple and cantilever, CC-combination continuous and cantilever, O-other. (DOI2)
Bridge Superstructure	Those elements of the bridge structure which are above the uppermost deck. (DOI4)
Bridle Line	The wire cable used to connect a barge in trailing fashion behind the towboat. (TNDOT1)
British Thermal Unit (Btu)	The quantity of heat needed to raise the temperature of 1 pound (approximately 1 pint) of water by 1 °F at or near 39.2 °F.
Broadcast	Transmission of information for which an acknowledgement is not expected. (FAA4)
Broken Train Collision	A collision in which a moving train breaks into parts and an impact occurs between these parts, or when a portion of the broken train collides with another consist. (FRA2)
Broker	(See also Customs House Broker; Freight Forwarder) A person who arranges for transportation of loads for a percentage of the revenue from the load. (MARAD2)
Brokerage	Freight forwarder/broker compensation as specified by ocean tariff. (MARAD2)
Brownie	Auxiliary transmission. (ATA1)
Brush Out	(See also Landscaping) To clear out the brush or vegetation around a light or day mark so that the structure is visible to navigation in all necessary directions. An aid should be cleared or brushed out so as to be completely visible to navigation from the beginning of its use in a set of marks until it is no longer being used in that or another set of marks. (TNDOT1)
Budget Authority	Empowerment by Congress that allows Federal agencies to incur obligations that will result in the outlay of funds. This empowerment is generally in the form of appropriations. However, for most of the highway programs, it is in the form of contract authority.
Budget Resolution	A concurrent resolution passed by Congress presenting the Congressional Budget for each of the succeeding 5 years. A concurrent resolution does not require the signature of the President.
Bug It	To carry freight from the front to the back of a truck. (ATA1)
Building Restriction Line (BRL)	A line which identifies suitable building area locations on airports. (FAA12)
Bulk Cargo	Cargo that is unbound as loaded; it is without count in a loose unpackaged form. Examples of bulk cargo include coal, grain, and petroleum products.
Bulk Carrier (Water)	A ship with specialized holds for carrying dry or liquid commodities, such as oil, grain, ore, and coal, in unpackaged bulk form. Bulk carriers may be designed to carry a single bulk product (crude oil tanker) or accommodate several bulk product types (ore/bulk/oil carrier) on the same voyage or on a subsequent voyage after holds are cleaned.
Bulk Carriers	All vessels designed to carry bulk cargo such as grain, fertilizers, ore and oil. (MARAD2)
Bulk Packaging	A packaging, other than a vessel or a barge, including a transport vehicle or freight container, in which hazardous materials are loaded with no intermediate form of containment and which has 1) A maximum capacity greater than 450 L (119 gallons) as a receptacle for a liquid; 2) A maximum net mass greater than 400 kg (882 pounds) and a maximum capacity greater than 450 L (119 gallons) as a receptacle for a solid; or 3) A water capacity greater than 454 kg (1000 pounds) as a receptacle for a gas as defined in 49 CFR 173.115. (49CFR171)
Bulk Terminal	A facility used primarily for the storage and/or marketing of petroleum products, which has a total bulk storage capacity of 50,000 barrels or more and/or receives petroleum products by tanker, barge, or pipeline. (DOE5)
Bulkhead	A partition separating one part of a ship, freight car, aircraft or truck from another part. (MARAD2)
Bull Hauler	One who hauls livestock. (ATA1)
Bulletin Board	A board located at each dam upon which is displayed information concerning the navigability of the dam, such as indicating when movable dams are down and open river conditions exist. Also located elsewhere such as at gages to publish gage readings and river level trend. (TNDOT1)
Bullnose	A slanted river ward end of the intermediate lock wall. (TNDOT1)
Bumble Bee	A two-cycle engine. (ATA1)
Bump	Usually used in the phrase "watch the bump," a term used on board tows when one or more barges are likely to make contact. May also mean a momentary grounding, usually due to excess speed in shallow water. (TNDOT1)
Bumpers	(See also Possum) 1) Fenders; 2) Pads made out of Styrofoam, old ropes,old tires, or similar material, which are hung over the side of a water vessel to prevent damage to the vessel when berthing or locking through dams. (TNDOT1)
Bunker	A storage tank. (DOE6)
Bunker C/Number 6 Fuel Oil	A high viscosity oil used mostly by ships, industry, and large-scale heating installations. This heavy fuel requires preheating in the storage tank to permit pumping and additional preheating to permit atomizing at the burners. (TNDOT1)
Bunkering Fuels	Fuels stored in ship bunkers. (DOE6)
Bunkers	Fuels supplied to ships and aircraft in international transportation, irrespective of the flag of the carrier, consisting primarily of residual, distillate, and jet fuel oils. (DOE5)
Buoy	A float moored or anchored in water. (DOI4)
Buoy Line	A line formed by two or more buoys marking a contour edge of a channel. (TNDOT1)
Buoy Range Markers	Painted stakes set up on shore so placed as to form a range through the exact location of a buoy. Used only on the Tennessee River to mark buoys in dredged cuts. (TNDOT1)
Bureau Of Economic Analysis (BEA)	The Bureau of Economic Analysis is an agency of the U.S. Department of Commerce
Bureau Of Labor Statistics (BLS)	The Bureau of Labor Statistics (BLS) is the principal fact-finding agency for the Federal Government in the broad field of labor economics and statistics. The BLS is an independent national statistical agency that collects, processes, analyzes, and disseminates essential statistical data to the American public, the U.S. Congress, other Federal agencies, State and local governments, business, and labor. The BLS also serves as a statistical resource to the Department of Labor. BLS data must satisfy a number of criteria, including relevance to current social and economic issues, timeliness in reflecting today’s rapidly changing economic conditions, accuracy and consistently high statistical quality, and impartiality in both subject matter and presentation.
Bureau of Transportation Statistics (BTS)	The Bureau was organized pursuant to section 6006 of the Intermodal Surface Transportation Efficiency Act (ISTEA) of 1991 (49 U.S.C. 111), and was formally established by the Secretary of Transportation on December 16, 1992. BTS has an intermodal transportation focus whose missions are to compile, analyze and make accessible information on the Nation's transportation systems; to collect information on intermodal transportation and other areas; and to enhance the quality and effectiveness of DOT's statistical programs through research, the development of guidelines, and the promotion of improvements in data acquisition and use. The programs of BTS are organized in six functional areas and are mandated by ISTEA to 1) Compile, analyze, and publish statistics 2) Develop a long-term data collection program 3) Develop guidelines to improve the credibility and effectiveness of the Department's statistics 4) Represent transportation interests in the statistical community 5) Make statistics accessible and understandable and 6) Identify data needs. (OFR1)
Bus	Large motor vehicle used to carry more than 10 passengers, including school buses, intercity buses, and transit buses.
Bus Charter Service (Except Local)	Establishments primarily engaged in furnishing passenger transportation charter service where such operations are principally outside a single municipality, outside one group of contiguous municipalities, or outside a single municipality and its suburban areas. (BOC1)
Bus Lane	1) A street or highway lane intended primarily for buses, either all day or during specified periods, but sometimes also used by carpools meeting requirements set out in traffic laws. (APTA1) 2) A lane reserved for bus use only. Sometimes also known as a "diamond lane."
Business District	The territory contiguous to and including a highway when within any 600 feet along such highway there are buildings in use for business or industrial purposes, including but not limited to hotels, banks, or office buildings which occupy at least 300 feet of frontage on one side or 300 feet collectively on both sides of the highway. (49CFR390)
Business Flying	The use of aircraft by pilots (not receiving direct salary or compensation for piloting) in connection with their occupation or in the furtherance of a private business. (NTSB2)
Business Transportation	Use of an aircraft not for compensation or hire by individuals for the purpose of transportation required by businesses in which they are engaged. (FAA2) (FAA9) (FAA10) (FAA14)
Busway	Exclusive freeway lane for buses and carpools. (APTA1)
Button	1) A heavy steel casting found mostly on lock walls, designed to hold the eye of a line or wire. It is also used as deck fittings on towboat and on barges. 2) A short mushroom-shaped bitt or a short timberhead. (TNDOT1)
Button Her Up	Tie down the load on a truck or trailer. (ATA1)
Cab	That portion of the superstructure designed to be occupied by the crew operating the locomotive. (49CFR229) The compartment of a locomotive from which the propelling power and power brakes of the train are manually controlled. (49CFR236) Portion of truck where the driver sits; tractor. The passenger compartment of a vehicle. (ATA1)
Cab Beside Engine	The cab is located to left or right side of the engine. (BOC3)
Cab Forward of the Engine	The engine is directly behind the cab. (BOC3)
Cab Over	A vehicle with a substantial part of its engine located under the cab. Also known as snubnose. (ATA1)
Cab Signal	A signal located in engineman's compartment or cab, indicating a condition affecting the movement of a train and used in conjunction with interlocking signals and in conjunction with or in lieu of block signals. (49CFR236)
Cabin Deck	The second deck on most river steamboats. It was lined with staterooms surrounding the main cabin. It was also called the Boiler deck even though the boilers were on the cargo deck below. (TNDOT1)
Cabin Motorboat	Motorboats with a cabin which can be completely closed by means of doors or hatches. Large motorboats with cabins, even though referred to as yachts, are considered to be cabin motorboats. (USCG2)
Cable Car	An electric railway operating in mixed street traffic with unpowered, individually-controlled transit vehicles propelled by moving cables located below the street surface and powered by engines or motors at a central location not on board the vehicle. (APTA1)
Cable Cars	Streetcar type of passenger vehicles operating by means of an attachment to a moving cable located below the street surface and powered by engines or motors at a central location not on board the vehicles. (FTA1)
Cableway	A conveyor system in which carrier units run on wire cables strung between supports. (DOI4)
Caboose	A car in a freight train intended to provide transportation for crew members. (49CFR223)
Cabotage	A law which requires coastal and intercoastal traffic to be carried by vessels belonging to the country owning the coast. (USTTA1)
Cab-Over-Engine (COE)	A truck or truck-tractor, having all, or the front portion, of the engine under the cab. (49CFR399)
Cab-Over-Engine (COE) High Profile	A COE having the door sill step above the height of the front tires. (49CFR399)
Cab-To-Axle Dimension (CA)	The distance from the back of a truck cab to the center line of the rear axle. For trucks with tandem rear axles, the CA dimension is given midway between the two rear axles. (GSA2)
Cackle Crate	Truck that hauls live poultry. (ATA1)
Cafe Standards	See Corporate Average Fuel Economy Standards.
Calculated Landing Time	A term that may be used in place of tentative or actual calculated landing time, whichever applies. (FAA4)
Calendar Year	The period of time between January 1 and December 31 of any given year. (DOE6)
Calibrated Airspeed	The indicated airspeed of an aircraft, corrected for position and instrument error. Calibrated airspeed is equal to true airspeed in standard atmosphere at sea level. (14CFR1)
Call For Release	Wherein the overlying Air Route Traffic Control Center (ARTCC) requires a terminal facility to initiate verbal coordination to secure Air Route Traffic Control Center (ARTCC) approval for release of a departure into the en route environment. (FAA4)
Call Up	Initial voice contact between a facility and an aircraft, using the identification of the unit being called and the unit initiating the call. (FAA4)
Camel Back Body	Truck body with floor curving downward at the rear. (ATA1)
Camp Car	Any on-track vehicle, including outfit, camp, or bunk cars or modular homes mounted on flat cars used to house rail employees. It does not include wreck trains. (49CFR218)
Campaign	A Defect/Noncompliance Campaign Program carried out by the manufacturer and initiated under 46 U.S.C. 4310. Starts as a case. A campaign may involve only one boat. (USCG1)
Canadian Minimum Navigation Performance Specification Airspace	That portion of Canadian domestic airspace within which Minimum Performance Specifications Airspace (MNPSA) separation may be applied. (FAA4)
Canal/Ditch	(See also Aqueduct) An artificial open waterway constructed to transport water, to irrigate or drain land, to connect two or more bodies of water, or to serve as a waterway for watercraft. (DOI3)
Canard	The forward wing of a canard configuration and may be a fixed, movable, or variable geometry surface, with or without control surfaces. (14CFR1)
Canard Configuration	A configuration in which the span of the forward wing is substantially less than that of the main wing. (14CFR1)
Cancellation of Insurance	The withdrawal of insurance coverage by either the insurer or the insured. (49CFR387)
Capacity	A transportation facility's ability to accommodate a moving stream of people or vehicles in a given time period.
Capacity Per Aircraft Mile	The average total passenger/cargo carrying capacity (tons) offered for sale per aircraft in revenue services, derived by dividing the overall available ton-miles by the total aircraft miles flown in revenue services. (BTS5)
Cape	A relatively extensive land area jutting into a water body, which prominently marks a change in or notably interrupts the coastal trend of that water body. (DOI4)
Capital Employee	An employee involved with construction or capital procurement and who has no involvement with operation of the transit system. (APTA1)
Capital Gains or Losses, Operating Property	Gains or losses on retirements of operating property and equipment, flight equipment expendable parts or miscellaneous materials and supplies when sold or otherwise retired in connection with a general retirement program as opposed to incidental sales performed as a service to others. (BTS4)
Capital Gains or Losses, Other	Gains or losses on no operating assets, investments in other than marketable equity securities, and troubled debt restructuring. (BTS4)
Capital Program Funds	Financial assistance from the Capital Program of 49 U.S.C. This program enables the Secretary of Transportation to make discretionary capital grants and loans to finance public transportation projects divided among fixed guideway (rail) modernization; construction of new fixed guideway systems and extensions to fixed guideway systems; and replacement, rehabilitation, and purchase of buses and rented equipment, and construction of bus-related facilities.
Capitalized Interest	Adjustment to income for interest capitalized on funds actually committed as equipment purchase deposits or actually used to finance the construction or acquisition of operating property. (BTS4)
Capsizing	Overturning of a vessel. The bottom must be uppermost, except on the case of a sailboat, which lies on its side. (USCG2)
Captain of the Port (COTP)	The officer of the Coast Guard, under the command of a District Commander, designated by the Commandant for the purpose of giving immediate direction to Coast Guard law enforcement activities within an assigned area. The term Captain of the Port includes an authorized representative of the Captain of the Port. (49CFR171)
Captive Imports	Products produced overseas specifically for domestic manufacturers. (DOE6)
Car	See also Automobile, Minivan, Motor Vehicle, Taxi, Vehicle.
Car Capacity	Load limitation of a freight car in terms of volume or weight. (AAR1)
Car Shop Repair Track Area	One or more tracks within an area in which the testing, servicing, repair, inspection, or rebuilding of railroad rolling equipment is under the exclusive control of mechanical department personnel. (49CFR218)
Carbon Dioxide (CO2)	1) A fluid consisting of more than 90 percent carbon dioxide molecules compressed to a supercritical state. (49CFR195) 2) A colorless, odorless gas. It is not a liquid under standard temperature and pressure.
Carbon Monoxide (CO)	A colorless, odorless, highly toxic gas that is a normal by-product of incomplete fossil fuel combustion. Carbon monoxide, one of the major air pollutants, can be harmful in small amounts if breathed over a certain period of time. (DOE6)
Carburetor	(See also Diesel Fuel System, Fuel Injection) A fuel delivery device for producing a proper mixture of gasoline vapor and air, and delivering it to the intake manifold of an internal combustion engine. Gasoline is gravity fed from a reservoir bowl into a throttle bore, where it is allowed to evaporate into the stream of air being inducted by the engine. The fuel efficiency of carburetors is more temperature dependent than fuel injection systems. (DOE4)
Cardinal Altitude	(See also Flight Level) "Odd" or "Even" thousand-foot altitudes or flight levels; e.g., 5,000, 6,000, 7,000, FL 250, FL 260, FL 270. (FAA4)
Carfloat	A vessel that operates on a short run on an irregular basis and serves one or more points in a port area as an extension of a rail line or highway over water, and does not operate in ocean, coastwise, or ferry service. (49CFR171)
Cargo	See also Commodity, Freight, Goods, Product.
Cargo Aircraft	An aircraft that is used to transport cargo and is not engaged in carrying passengers. The terms cargo aircraft only, cargo-only aircraft and cargo aircraft have the same meaning. (49CFR171)
Cargo Crane	A crane especially adapted to the transferring of cargo between a vessel's hold and a wharf. (TNDOT1)
Cargo Insurance and Freight (CIF)	Refers to cargos for which the seller pays for the transportation and insurance up to the port of destination. (DOE5)
Cargo Ramp	A dedicated load/unload facility for cargo aircraft.
Cargo Tank	A bulk packaging which 1) Is a tank intended primarily for the carriage of liquids or gases and includes appurtenances, reinforcements, fittings, and closures; 2) Is permanently attached to or forms a part of a motor vehicle, or is not permanently attached to a motor vehicle but which, by reason of its size. construction or attachment to a motor vehicle is loaded or unloaded without being removed from the motor vehicle; and 3) Is not fabricated under a specification for cylinders, portable tanks, tank cars, or multi-unit tank car tanks. (49CFR171)
Cargo Tank Motor Vehicle	A motor vehicle with one or more cargo tanks permanently attached to or forming an integral part of the motor vehicle. (49CFR171)
Cargo Ton-Miles	One ton of cargo transported one mile. (BTS6)
Cargo Tonnes	The tonnes of cargo carried by a vessel on each or any transit. (SLSDC1)
Cargo Transfer System	A component, or system of components functioning as a unit, used exclusively for transferring hazardous fluids in bulk between a tank car, tank truck, or marine vessel and a storage tank. (49CFR193)
Cargo Vessel	1) Any vessel other than a passenger vessel; 2) any ferry being operated under authority of a change of character certificate issued by a Coast Guard Officer-in-Charge, Marine Inspection. (49CFR171)
Cargo-Carrying Unit	Any portion of a commercial motor vehicle (CMV) combination (other than a truck tractor) used for the carrying of cargo, including a trailer, semitrailer, or the cargo-carrying section of a single-unit truck. (23CFR658)
Carload	Quantity of freight (in tons) required to fill a railcar; amount normally required to qualify for a carload rate.
Car-Mile	The movement of a car a distance of one mile. (AAR1)
Car-Mile (Rail)	The movement of a railroad car a distance of one mile. An empty or loaded car-mile refers to a mile run by a freight car with or without a load. In the case of intermodal movements, the designation of empty or loaded refers to whether the trailers or containers are moved with or without a waybill.
Carpool	An arrangement where two or more people share the use and cost of privately owned automobiles in traveling to and from pre-arranged destinations together. (ATPA1)
Carried Carload	Any carload which travels on a particular railroad. (AAR1)
Carrier	A person engaged in the transportation of passengers or property by land or water, as a common, contract, or private carrier; or civil aircraft. (49CFR171)
Carrier Group	A grouping of certificated air carriers determined by annual operating revenues as shown below Majors $1 billion +; Nationals $100 million to $1 billion; Large regionals $20 million to $99.9 million; Medium regionals 0 to $19.9 million or that operate aircraft with 60 or less seats or maximum payload capacity of 18,000 lbs. (FAA2) (FAA15)
Carrier Liability	A common carrier is liable for all loss, damage, and delay with the exception of act of God, act of a public enemy, act of a public authority, act of the shipper, and the inherent nature of the goods. Carrier liability is specified in the terms of the bill of lading. (MARAD1)
Carrier Type	"For-hire", private or "other." (FHWA2) (FHWA4)
Cartage	Usually refers to intra-city hauling on drays or trucks. (MARAD2)
Case	An investigation of a particular boating problem or incident to determine if there is a substantial risk to the public or violation of the regulations. A case may become a campaign. (USCG1)
Casualty	See also Accident, Collision, Crash, Derailment, Fatality, Event, Incident, Injury, Personal Casualties terms.
Category	1) As used with respect to the certification, ratings, privileges, and limitations of airmen, means a broad classification of aircraft. Examples include airplane; rotor craft; glider; and lighter-than-air; and 2) As used with respect to the certification of aircraft, means a grouping of aircraft based upon intended use or operating limitations. Examples include transport, normal, utility, acrobatic, limited, restricted, and provisional. (14CFR1)
Category A	With respect to transport category rotorcraft, means multi-engine rotorcraft designed with engine and system isolation features specified in 14CFR Part 29 and utilizing scheduled takeoff and landing operations under a critical engine failure concept which assures adequate designated surface area and adequate performance capability for continued safe flight in the event of engine failure. (14CFR1)
Category B	With respect to transport category rotorcraft, means single-engine or multi-engine rotorcraft which do not fully meet all Category A standards. Category B rotorcraft have no guaranteed stay-up ability in the event of engine failure and unscheduled landing is assumed. (14CFR1)
Category II Operations	With respect to the operation of aircraft, means a straight-in Instrument Landing System (ILS) approach to the runway of an airport under a Category II ILS instrument approach procedure issued by the [Federal Aviation Administration] Administrator or other appropriate authority. (14CFR1)
Category III Operations	With respect to the operation of aircraft, means an Instrument Landing System (ILS) approach to, and landing on, the runway of an airport using a Category III ILS instrument approach procedure issued by the [Federal Aviation Administration] Administrator or other appropriate authority. (14CFR1)
Caval	See Kevel.
Caving Bank	A bank which is eroding because of swift running currents along the shore or because of eddies below bends or along the shoreline whether on right-or left-handed drafts. More prevalent on rivers with unstable channels and during periods of high water; very common occurrence on the Lower Mississippi River. (TNDOT1)
Ceiling	1) The height above the earth's surface of the lowest layer of clouds or obscuring phenomena that is reported as "broken", "overcast", or "obscuration", and not classified as "thin" or "partial". 2) The height above the ground or water of the base of the lowest layer of the cloud below 6,000 meters (20,000 feet) covering more than half the sky. (14CFR1) (FAA4)
Cement Mixer	Truck with a noisy engine or transmission. (ATA1)
Census	The complete enumeration of a population or groups at a point in time with respect to well-defined characteristics for example, population,production, traffic on particular roads. In some connection the term is associated with the data collected rather than the extent of the collection so that the term sample census has a distinct meaning. The partial enumeration resulting from a failure to cover the whole population, as distinct from a designed sample enquiry, may be referred to as an "incomplete census." (DOE5)
Census Division	A geographic area consisting of several States defined by the U.S. Department of Commerce, Bureau of the Census. The States are grouped into nine divisions and four regions. (DOE4)
Center Area	The specified airspace within which an Air Route Traffic Control Center (ARTCC) provides air traffic control and advisory service. (FAA4) (FAA14)
Center Radar Approach Control (CERAP)	A combined Air Route Traffic Control Center (ARTCC) and a Terminal Radar Approach Control facility (TRACON). (FAA13) (FAA14)
Center Weather Advisory (CWA)	An unscheduled weather advisory issued by Center Weather Service Unit meteorologists for Air Traffic Control (ATC) use to alert pilots of existing or anticipated adverse weather conditions within the next 2 hours. A CWA may modify or redefine a SIGMET. (FAA4)
Central Business District (CBD)	The downtown retail trade and commercial area of a city or an area of very high land valuation, traffic flow, and concentration of retail business offices, theaters, hotels and services. (APTA1)
Central City	(See also Metropolitan Statistical Area, Standard Metropolitan Statistical Area) Usually one or more legally incorporated cities within the Metropolitan Statistical Area (MSA) that is significantly large by itself or large relative to the largest city in the MSA. Additional criteria for being classified as "Central City" include having at least 75 jobs for each 100 employed residents and having at least 40 percent of the resident workers employed within the city limits. Every MSA has at least one central city, usually the largest city. Central cities are commonly regarded as relatively large communities with a denser population and a higher concentration of economic activities than the outlying or suburban areas of the MSA. "Outside Central City" are those parts of the MSA not designated as central city. (DOE4)
Central East Pacific	An organized route system between the U.S. West Coast and Hawaii. (FAA4)
Certificate of Inspection	A document certifying that merchandise (such as perishable goods) was in good condition immediately prior to shipment. Preshipment inspection is a requirement for importation of goods into many developing countries. (USTTA1)
Certificate of Origin	A form showing the country of production of export shipment, frequently required by customs officials of an importing country. The certificate enables customs officials to determine which goods being imported are entitled to preferential tariff treatment. It is usually endorsed by a consular official of the country of destination at the port of shipment. (TNDOT1)
Certificate of Public Convenience and Necessity	1) A certificate issued to an air carrier under Section 401 of the Federal Aviation Act by Department of Transportation (DOT) authorizing the carrier to engage in air transportation. 2) The grant of operating authority (issued by the Interstate Commerce Commission, ICC; and the Federal Maritime Commission, (FMC) that is given to common carriers. A carrier must prove that a public need exists and that the carrier is fit, willing and able to provide the needed service. The certificate may specify the commodities to be hauled, the area to be served, and the routes to be used. (FAA4) (FAA11) (FAA15)
Certificate Of Public Convenience And Necessity (Air Carrier)	A certificate issued by the U.S. Department of Transportation to an air carrier under Section 401 of the Federal Aviation Act authorizing the carrier to engage in air transportation.
Certificated	Holding a currently valid Certificate of Public Convenience and Necessity. (FAA15)
Certificated Air Carrier	An air carrier holding a Certificate of Public Convenience and Necessity issued by the U.S. Department of Transportation to conduct scheduled services interstate. These carriers may also conduct nonscheduled or charter operations. Certificated air carriers operate large aircraft (30 seats or more or a maximum load of 7,500 pounds or more) in accordance with FAR Part 121. See also Large Certificated Air Carrier.
Certificated Airport	An airport operating under Federal Aviation Regulations (FAR) Part 139. The Federal Aviation Administration (FAA) issues airport operating certificates to all airports serving scheduled air carrier aircraft designed for more than 30 passenger seats. Certificated airports must meet minimum safety standards in accordance with Federal Aviation Regulations (FAR) Part 139. (FAA3)
Certificated Airports	Airports that service air carrier operations with aircraft seating more than 30 passengers.
Certification Acceptance ((CA))	A procedure authorized by 23 U.S.C. 117(a) wherein the FHWA can delegate any of the 23 U.S.C. responsibilities for planning, design, and construction of projects, not on the Interstate System, to other qualified governmental entities. {This section of law was deleted in the Transportation Equity Act for the 21st Century. CA is being replaced by Stewardship Agreements. BIA area offices and ITGs may apply for Stewardship Agreements.}
Certification of Public Road Mileage	An annual document (certification) that must be furnished by each state to Federal Highway Administration (FHWA) certifying the total public road mileage (kilometers) in the state as of December 31 of the preceding year. (FHWA2)
Certified Capacity	The capability of a pipeline project to move gas volumes on a given day, based on a specific set of flowing parameters (operating pressures, temperature, efficiency, and fluid properties) for the pipeline system as stated in the dockets filed (and subsequently certified) in the application for the Certificate of Public Convenience and Necessity at the Federal Energy Regulatory Commission. Generally, the certificated capacity represents a level of service that can be maintained over an extended period of time and may not represent the maximum throughput capability of the system on any given day. (DOE1)
Certified Glazing	A glazing material that has been certified by the manufacturer as having met the testing requirements set forth in Appendix A of 49 CFR 223 and that has been installed in such a manner that it will perform its intended function. (49CFR223)
Chaff	Thin, narrow metallic reflectors of various lengths and frequency responses, used to reflect radar energy. These reflectors when dropped from aircraft and allowed to drift downward result in large targets on the radar display. (FAA4)
Chained Dollars	A measure used to express real prices, defined as prices that are adjusted to remove the effect of changes in the purchasing power of the dollar. Real prices usually reflect buying power relative to a reference year. The “chained-dollar” measure is based on the average weights of goods and services in successive pairs of years. It is “chained” because the second year in each pair, with its weights, becomes the first year of the next pair. Prior to 1996, real prices were expressed in constant dollars, a weighted measure of goods and services in a single year. See also Constant Dollar and Current Dollar.
Chair	See Sidecar.
Chamber Time	Total time tow is in the chamber from entry to exit. (TNDOT1)
Channel Bottom	Project depth or grade elevation. (TNDOT1)
Channel Gradient	The slope of the water surface of a stream channel through the bridge site to the nearest one tenth of a percent. (DOI2)
Channel Meander	An unstable river channel which changes its location after high water periods. (TNDOT1)
Channel Report	A report of channel conditions, soundings, etc., found by an aids to navigation tender on routine patrol; includes report of courses steered. The channel report is issued only for open rivers and is written in pilots' jargon. (TNDOT1)
Channel Width	The upstream channel width (bank to bank dimensions of the defined channel, not the flood plain) at a bridge site; to the nearest foot. (DOI2)
Channoine Weir	A section of a dam, built in the form of a spillway, lying between the anchor weir proper on the land side of a lock wall and the bear trap which is adjacent to the navigable path. (TNDOT1)
Character of Vessel	The type of service in which the vessel is engaged at the time of carriage of a hazardous material. (49CFR171)
Charge It	Let brake air flow into semitrailer lines. (ATA1)
Charted Visual Flight Procedure Approach	An approach wherein a radar-controlled aircraft on an Instrument Flight Rules (IFR) Flight plan, operating in Visual Flight Rules (VFR) conditions and having an Air Traffic Control (ATC) authorization, may proceed to the airport of intended landing via visual landmarks and altitudes depicted on a charted visual flight procedure. (FAA4)
Charted Visual Flight Rules (VFR) Flyways	Flight paths recommended for use to bypass areas heavily traversed by large turbine-powered aircraft. Pilot compliance with recommended flyways and associated altitudes is strictly voluntary. Visual Flight Rules (VFR) Flyway Planning charts are published on the back of existing Visual Flight Rules (VFR) Terminal Area charts. (FAA4)
Charter Bus	A bus transporting a group of persons who pursuant to a common purpose, and under a single contract at a fixed price, have acquired the exclusive use of a bus to travel together under an itinerary. (APTA1)
Charter Party	Contract between the owner of a vessel and a shipper for letting of the vessel or a part thereof. (TNDOT1)
Charter Service	A commercial passenger vehicle trip not scheduled, but specially arranged. The charter contract normally commits the carrier to furnish the agreed to transportation service at a specified time between designated locations. (FHWA2)
Charter Service Hours	The total hours traveled/operated by a revenue vehicle while in charter service. Charter service hours include hours traveled/operated while carrying passengers for hire, plus associated deadhead hours. (FTA1)
Charter Transportation of Passengers	Transportation, using a bus, of a group of persons who pursuant to a common purpose, under a single contract, at a fixed charge for the vehicle, have acquired the exclusive use of the vehicle to travel together under an itinerary either specified in advance or modified after having left the place of origin. (49CFR390)
Chase	An aircraft flown in proximity to another aircraft normally to observe its performance during training or testing. (FAA4)
Chassis	A trailer type device with wheels constructed to accommodate containers, which are lifted on and off.
Chassis Cab	An incomplete vehicle consisting of a cab on a bare frame rail chassis, needing a body or load platform in order to become complete. (TII1) (TII2)
Cheater Bar	See Breakdown Bar.
Check Line	A line used to help check a boat's headway when landing or entering a lock. (TNDOT1)
Check Post	A mooring bit on a lock wall. (TNDOT1)
Checked Baggage	Baggage accepted by the air carrier for transportation in the hold of the aircraft. (FAA1)
Chicago Grips	A colloquial term used for a wire come-along used in hoisting wire rope. (TNDOT1)
Chief Hood Lifter	Garage superintendent. (ATA1)
Chunk	Differential housing on powered axles. (ATA1)
Chute	1) Section of river that is narrower than ordinary and through which the river current increases, often navigable from bank to bank. 2) a narrow sloping passage by which water falls or flows to a lower level (between an island and a bank). (TNDOT1)
Circle to Land Maneuver	A maneuver initiated by the pilot to align the aircraft with a runway for landing when a straight-in landing from an instrument approach is not possible or is not desirable. This maneuver is made only after Air Traffic Control (ATC) authorization has been obtained and the pilot has established required visual reference to the airport. (FAA4)
Circle to Runway (Runway Number) Maneuver	Used by Air Traffic Control (ATC) to inform the pilot that he must circle to land because the runway in use is other than the runway aligned with the instrument approach procedure. When the direction of the circling maneuver in relation to the airport/runway is required, the controller will state the direction (eight cardinal compass points) and specify a left or right downwind or base leg as appropriate; (e.g., "Cleared Very High Frequency Omni-Directional Radio Range (VOR) Runway Three Six Approach circle to Runway Two," or "Circle northwest of the airport for a right downwind to Runway Two."). (FAA4)
Circling Approach	See Circle to Land Maneuver.
Circuit	A conductor or a system of conductors through which electric current flows. (DOE5)
Circuit Controller	A device for opening and closing electric circuits. (49CFR236)
Circuit-Mile	The total length in miles of separate circuits regardless of the number of conductors used per circuit. (DOE5)
Circulator Bus	A bus serving an area confined to a specific locale, such as a downtown area or suburban neighborhood with connections to major traffic corridors. (APTA1)
Circus Wagon	Low sided trailer with high bow tarp. (ATA1)
City Flyer	Short, low trailer with high bow tarp. (ATA1)
City Gate	A point or measuring station at which a distribution gas utility receives gas from a natural gas pipeline company or transmission system. (DOE3)
City Trip	A commercial vehicle trip within a single city, town, county, or other geographic jurisdiction. (FHWA2)
Civil Aircraft	Aircraft other than public aircraft. (14CFR1)
Class	1) With respect to the certification, ratings, privileges, and limitations of airmen, means a classification of aircraft within a category having similar operating characteristics. Examples include single engine; multiengine; land; water; gyroplane; helicopter; airship; and free balloon; and 2) With respect to the certification of aircraft, means a broad grouping of aircraft having similar characteristics of propulsion, flight, or landing. Examples include airplane; rotorcraft; glider; balloon; landplane; and seaplane. (14CFR1)
Class 1 Road	Hard surface highways including Interstate and U.S. numbered highways (including alternates), primary State routes, and all controlled access highways. (DOI3)
Class 2 Road	Hard surface highways including secondary State routes, primary county routes, and other highways that connect principal cities and towns, and link these places with the primary highway system. (DOI3)
Class 3 Road	Hard surface roads not included in a higher class and improved, loose surface roads passable in all kinds of weather. These roads are adjuncts to the primary and secondary highway systems. Also included are important private roads such as main logging or industrial roads which serve as connecting links to the regular road network. (DOI3)
Class 4 Road	Unimproved roads which are generally passable only in fair weather and used mostly for local traffic. Also included are driveways, regardless of construction. (DOI3)
Class 5 Road	Unimproved roads passable only with 4 wheel drive vehicles. (DOI3)
Class A and B Explosives In Bulk	The transportation, as cargo, of any Class A or B explosive(s) in any quantity. (49CFR387)
Class A By Inland and Coastal Waterways Carrier	A class A carrier by water is one with an average annual operation revenue that exceeds $500,000. (TNDOT1)
Class B By Inland and Coastal Waterways Carrier	A class B carrier by water is one with an average annual operating revenue greater than $100,000 but less than $500,000. (TNDOT1)
Class I Freight Railroad	Defined by the Interstate Commerce Commission each year based on annual operating revenue. For 1988, the threshold for Class I railroads was $87.9 million. A railroad is dropped from the Class I list if it fails to meet the annual earnings threshold for three consecutive years. (DOE6)
Class I Motor Carrier	Motor carrier with annual revenues greater than $10 million. Prior to January 1, 1994, the revenue classification level was $5 million. (ATA2)
Class I Railroad	Railroad with an annual operating revenue of at least $266.7 million.
Class II Motor Carrier	Motor carrier with annual revenues between $3 and $10 million. Prior to January 1, 1994, the revenue classification level was between $1 and $5 million. (ATA2)
Class III Motor Carrier	Motor carrier with annual revenues under $1 million. Prior to January 1, 1994, the revenue classification level was under $1 million. (ATA2)
Class I-VIII Truck	Trucks with the following gross vehicle weight (GVW) (ATA2)
Classification Yard	A railroad terminal area where railcars are grouped together to form train units.
Claused Bill of Lading	A bill of lading which has exceptions to the receipt of merchandise in "apparent good order" noted. (TNDOT1)
Clean Air Act Amendments (CAAA)	The original Clean Air Act was passed in 1963, but the national air pollution control program is actually based on the 1970 version of the law. The 1990 Clean Air Act Amendments are the most far-reaching revisions of the 1970 law. The 1990 Clean Air Act is the most recent version of the 1970 version of the law. The 1990 amendments made major changes in the Clean Air Act.
Clean Bill of Lading	A bill of lading which covers goods received in apparent good order and condition and without qualification. (TNDOT1)
Clean Bore	A single tank without compartments inside. (ATA1)
Clean Fuel Vehicle	Vehicle meeting the clean fuel vehicle exhaust emissions standards with no restriction on fuel type. (DOE6)
Clear Air Turbulence (CAT)	Turbulence encountered in air where no clouds are present. This term is commonly applied to high-level turbulence associated with wind shear. CAT is often encountered in the vicinity of the jet stream. (FAA4)
Clear of the Runway	1) A taxiing aircraft, which is approaching a runway, is clear of the runway when all parts of the aircraft are held short of the applicable holding position marking. 2) A pilot or controller may consider an aircraft, which is exiting or crossing a runway, to be clear of the runway when all parts of the aircraft are beyond the runway edge and there is no Air Traffic Control (ATC) Federal Aviation Administration (FAA) Glossary C 2 restriction to its continued movement beyond the applicable holding position marking. 3) Pilots and controllers shall exercise good judgement to ensure that adequate separation exists between all aircraft on runways and taxiways at airports with inadequate runway edge lines or holding position markings. (FAA4)
Clearance	See also Cleared terms.
Clearance Lamp	A lamp used on the front and the rear of a motor vehicle to indicate its overall width and height. (49CFR393)
Clearance Limit	The fix, point, or location to which an aircraft is cleared when issued an air traffic clearance. (FAA4)
Clearance Traffic Control	Authorization for an aircraft to proceed under conditions specified by an air traffic control unit. (FAA4)
Clearance Void If Not Off By Time	Used by Air Traffic Control (ATC) to advise an aircraft that the departure clearance is automatically canceled if takeoff is not made prior to a specified time. The pilot must obtain a new clearance or cancel his Instrument Flight Rules (IFR) flight plan if not off by the specified time. (FAA4)
Clearance Void Time	A time specified by an air traffic control unit at which a clearance ceases to be valid unless the aircraft concerned has already taken action to comply therewith. (FAA4)
Cleared	See also Clearance.
Cleared Approach	Air Traffic Controller (ATC) authorization for an aircraft to execute any standard or special instrument approach procedure for that airport. Normally, an aircraft will be cleared for a specific instrument approach procedure. (FAA4)
Cleared as Filed	Means the aircraft is cleared to proceed in accordance with the route of flight filed in the flight plan. This clearance does not include the altitude, standard instrument departure (SID), or SID transition. (FAA4)
Cleared For Takeoff	Air Traffic Control (ATC) authorization for an aircraft to depart. It is predicated on known traffic and known physical airport conditions. (FAA4)
Cleared For the Option	Air Traffic Control (ATC) authorization for an aircraft to make a touch-and-go, low approach, missed approach, stop and go, or full stop landing at the discretion of the pilot. It is normally used in training so that an instructor can evaluate a student's performance under changing situations. Also known as Option Approach. (FAA4)
Cleared Through	Air Traffic Control (ATC) authorization for an aircraft to make intermediate stops at specified airports without refiling a flight plan while enroute to the clearance limit. (FAA4)
Cleared to Land	Air Traffic Control (ATC) authorization for an aircraft to land. It is predicated on known traffic and known physical airport conditions. (FAA4)
Clearway	1) For turbine engine powered airplanes certificated after August 29, 1959, an area beyond the runway, not less than 500 feet wide, centrally located about the extended centerline of the runway, and under the control of the airport authorities. The clear
Climb to VFR	Air Traffic Control (ATC) authorization for an aircraft to climb to Visual Flight Rules (VFR) conditions within clause B, C, D, and E surface areas when the only weather limitation is restricted visibility. The aircraft must remain clear of clouds while climbing to Visual Flight Rules (VFR). (FAA4)
Climbout	That portion of flight operation between takeoff and the initial cruising altitude. (FAA4)
Climbout Speed	With respect to rotorcraft, means a referenced airspeed which results in a flight path clear of the height-velocity envelope during initial climbout. (14CFR1)
Close the Gates	Close rear doors of trailer. (ATA1)
Closed Runway	A runway that is unusable for aircraft operations. Only the airport management/military operations office can close a runway. (FAA4)
Closed Traffic	Successive operations involving takeoffs and landings or low approaches where the aircraft does not exit the traffic pattern. (FAA4)
Closing Dam	An earthen, sand, rock, or rock and brush structure built across slough or back channel to stop current flow at water stages below the crest elevation of the structure. Low flows are thus diverted to the main channel. (TNDOT1)
Clutter	In radar operations, clutter refers to the reception and visual display of radar returns caused by precipitation, chaff, terrain, numerous aircraft targets, or other phenomena. Such returns may limit or preclude Air Traffic Control (ATC) from providing services based on radar. (FAA4)
Coach Passenger Revenue	Revenues from the air transportation of passengers moving at fares reduced from the first class or premium fares which are predicated upon both the operation of specifically designated aircraft space and a reduction in the quality of service regularly and ordinarily provided. (BTS4)
Coach Service	Transport service established for the carriage of passengers at special reduced passenger fares that are predicated on both the operation of specifically designed aircraft space and a reduction in the quality of service regularly and ordinarily provided. (BTS5)
Coal	A black or brownish-black solid, combustible substance formed by the partial decomposition of vegetable matter without access to air. The rank of coal, which includes anthracite, bituminous coal, subbituminous coal, and lignite, is based on fixed carbon, volatile matter, and heating value. Coal rank indicates the progressive alteration, or coalification, from lignite to anthracite. Lignite contains approximately 9 to 17 million British Thermal Unit (BTU) per ton. The heat contents of subbituminous and bituminous coal range from 16 to 24 million BTU per ton, and from 19 to 30 million BTU per ton, respectively. Anthracite contains approximately 22 to 28 million BTU per ton. (DOE3)
Coal Slurry	Finely crushed coal mixed with sufficient water to form a fluid. (DOE6)
Coastal	Means transits to or from the Maritimes and U.S. Atlantic Ports. (SLSDC1)
Coastal Air Defense Identification Zone (ADIZ)	An Air Defense Identification Zone (ADIZ) over the coastal waters of the United States. (FAA4)
Coastal Fix	A navigation aid or intersection where an aircraft transitions between the domestic route structure and the oceanic route structure. (FAA4)
Coastal Shipping	Also known as short-sea or coastwise shipping, describes marine shipping operations between ports along a single coast or involving a short sea crossing.
Coastal Zone	All United States waters subject to the tide, waters of the Great Lakes and Lake Champlain, specified ports and harbors on inland rivers, waters of the contiguous zone, other waters of the high seas subject to the National Contingency Plan, and the land surface or land substrate, ground waters, and ambient air proximal to those waters. The term "coastal zone" delineates an area of federal responsibility for response action. Precise boundaries are determined by agreements between the Environmental Protection Agency (EPA) and the U.S. Coast Guard (USCG), and are identified in Federal Regional Contingency Plans and Area Contingency Plans. (49CFR194)
Coastwise Traffic	Domestic traffic which moves over the ocean, or the Gulf of Mexico, e.g., between New Orleans and Baltimore, New York and Puerto Rico, San Francisco and Hawaii, Puerto Rico and Hawaii. Traffic between Great Lakes ports and seacoast ports, when having a carriage over the ocean, is also deemed to be coastwise. The Chesapeake Bay and Puget Sound are considered internal bodies of water rather than arms of the ocean; traffic confined to these areas is deemed to be "internal" rather than coastwise. (TNDOT1)
Coastwise Traffic (Water)	Domestic traffic receiving a carriage over the ocean or the Gulf of Mexico (e.g., between New Orleans and Baltimore, New York and Puerto Rico, San Francisco and Hawaii, Alaska and Hawaii). Traffic between Great Lakes ports and seacoast ports, when having a carriage over the ocean, is also considered coastwise.
Code	See also Decoder, Discrete Code.
Code of Federal Regulations (CFR)	A compilation of the general and permanent rules of the executive departments and agencies of the Federal Government as published in the Federal Register. The code is divided into 50 titles that represent broad areas subject to Federal regulation. (DOE5)
Coded Track Circuit	A track circuit in which the energy is varied or interrupted periodically. (49CFR236)
Cofferdam	An enclosure from which the water can be pumped to expose the bottom of a river for the purposes of construction. (TNDOT1)
Coffin-Box	Sleeper compartment independent of truck cab. (ATA1)
Cognizant Officer In Charge of Marine Inspection (OCMI)	The Officer in Charge Marine Inspection in which the manufacturer responsible for defect notification (or other corrective action) is located. Commandant (G-MVI) directs specific actions for OCMIs to take in cases where a single cognizant OCMI cannot be identified. (USCG1)
Coincidental Peak-Day Flow	The volume of gas that moves through a pipeline or section thereof or is delivered to a customer on the day of the year when the pipeline system handles the largest volume of gas. (DOE1)
Collector (Highway)	In rural areas, routes that serve intracounty rather than statewide travel. In urban areas, streets that provide direct access to neighborhoods and arterials.
Collector Highway	Collector highways are those highways which link local highways to arterial highways. (FHWA5)
Collectors	In rural areas, routes serving intra-county, rather than statewide travel. In urban areas, streets providing direct access to neighborhoods as well as direct access to arterials. (NHTSA3)
Collision	See also Accident, Casualty, Crash, Derailment, Event, Fatality, Incident, Injury, Truck Crash.
Collision Accident	An accident involving a collision between a commercial motor vehicle and another object. Collision objects include trains, other motor vehicles pedestrians, bicyclists, animals and fixed objects. (FHWA2) (FHWA4)
Collision Between Aircraft	Is so classified only when both aircraft are occupied. This includes collisions wherein both aircraft are airborne (midair); both on the ground or where one is airborne and the other on the ground. A collision with a parked unoccupied aircraft is classified under the broad category of collision with objects. (NTSB1) (NTSB2)
Collision With Another Vessel	Any striking together of two or more vessels, regardless of operation at time of the accident, is a collision. (Also includes colliding with the tow of another vessel, regardless of the nature of the tow, i.e., surfboard, ski ropes, tow line, etc.) (USCG2)
Collision With Fixed Object	The striking of any fixed object, above or below the surface of the water. (USCG2)
Collision With Floating Object	Collision with any waterborne object above or below the surface that is free to move with the tide, current, or wind, except another vessel. (USCG2)
Collision With Object	An incident in which a transit vehicle strikes an obstacle other than a vehicle or person (e.g., building, utility pole). Reports are made if the accident results in a death, injury, or property damage over $1,000. (FTA2)
Collision With Objects	Where an occupied aircraft collides with a parked unoccupied aircraft or some other object. (NTSB1) (NTSB2)
Collision With Other Vehicles	An incident involving one or more transit agency vehicles and any other vehicle. Report collisions between rail cars from coupling operations. Report fatalities or injuries that occur inside the transit vehicle as well as fatalities or injuries that occur inside other involved vehicles. (FTA1)
Collision With People	An incident in which a transit vehicle strikes a person. Except where specifically indicated, collisions with people do not include suicide attempts. Reports are made if the incident results in death, injury, or property damage over $1,000. (FTA2)
Collision With Vehicle	An incident in which a transit vehicle strikes or is struck by another vehicle. Reports are made if the accident results in death, injury, or property damage over $1,000. (FTA2)
Combination Export Manager	A firm which acts as an export sales agent for two or more U.S. manufacturers, all of which are noncompetitive with the others. (TNDOT1)
Combination Packaging	A combination of packaging, for transport purposes, consisting of one or more inner packagings secured in a non-bulk outer packaging. It does not include a composite packaging. (49CFR171)
Combination Passenger and Cargo Ships	Ships with a capacity for 13 or more passengers. (MARAD2)
Combination Trailer	A trailer used to handle freight in the transportation of goods for others; excludes house trailers, light farm trailers and car trailers. (ATA2)
Combination Truck	A power unit (truck tractor) and one or more trailing units (a semitrailer or trailer).
Combined Center	An air traffic facility which combines the functions of an air route traffic control center and a radar approach control facility. (FAA4)
Combined Household Energy Expenditures	1) The total amount of funds spent for energy consumed in, or delivered to, a housing unit during a given period of time and for fuel used to operate the motor vehicles that are owned or used on a regular basis by the household. 2) The total dollar amount for energy consumed in a housing unit includes state and local taxes but excludes merchandise repairs or special service charges. Electricity, and natural gas expenditures are for the amount of those energy sources consumed. Fuel oil, kerosene, and LPG expenditures are for the amount of fuel purchased, which may differ from the amount of fuel consumed; 3) The total dollar amount of fuel spent for vehicles is the product of fuel consumption and price. (DOE4)
Come Aboard	A greeting when guests come on the boat. (TNDOT1)
Commerce	Any trade, traffic or transportation within the jurisdiction of the United States between a place in a State and a place outside of such State, including a place outside of the United States and trade, traffic, and transportation in the United States which affects any trade, traffic, and transportation described in the first part of this definition. (49CFR383)
Commercial Air Carrier	An air carrier certificated in accordance with Federal Aviation Regulations (FAR) Part 121 or 127 to conduct scheduled services on specified routes. These air carriers may also provide non-scheduled or charter services as a secondary operation. Four carrier groupings have been designated for statistical and financial data aggregation and analysis. Majors (annual operating revenues greater than $1 billion), Nationals (annual operating revenues between $100 million and $1 billion), Large Regionals (annual operating revenues between $10 million and $99,999,999), Medium Regionals (annual operating revenues less than $10 million). (FAA1) (FAA14)
Commercial Airport	(See also Commercial Service Airport) A public airport which is determined to enplane annually 2,500 or more passengers and receive scheduled passenger service of aircraft. (FAA2)
Commercial Body	A body type not normally furnished by the original equipment manufacturer as a standard option but available from other manufacturers; (e.g., dump, compactor tank, and utility). (GSA2)
Commercial Bus	Any bus used to carry passengers at rates specified in tariffs; charges may be computed per passenger (as in regular route service) or per vehicle (as in charter service).
Commercial Driver's License (CDL)	A license issued by a State or other jurisdiction, in accordance with the standards contained in 49 CFR 383, to an individual which authorizes the individual to operate a class of a commercial motor vehicle. (49CFR383)
Commercial Driver's License Information System (CDLIS)	Established by Federal Highway Administration (FHWA) pursuant to section 12007 of the Commercial Motor Vehicle Safety Act of 1986. (49CFR383)
Commercial Invoice	A document of the transaction between a buyer and a seller. (TNDOT1)
Commercial Motor Vehicle (CMV)	A motor vehicle or combination of motor vehicles used in commerce to transport passengers or property if the motor vehicle 1) Has a gross combination weight rating of 26,001 or more pounds inclusive of a towed unit with a gross vehicle weight rating of more than 10,000 pounds; or 2) Has a gross vehicle weight rating of 26,001 or more pounds, or 3) Is designed to transport 16 or more passengers, including the driver; or 4) Is of any size and is used in the transportation of materials found to be hazardous for the purposes of the Hazardous Materials Transportation Act and which require the motor vehicle to be placarded under the Hazardous Materials Regulations (49 CFR 172, subpart F). (49CFR383)
Commercial Motor Vehicle Traffic Violation	See Serious Traffic Violation.
Commercial Operator	A person who, for compensation or hire, engages in the carriage by aircraft in air commerce of persons or property, other than as an air carrier or foreign air carrier or under the authority of Part 375 of this title. Where it is doubtful that an operation is for "compensation or hire", the test applied is whether the carriage by air is merely incidental to the person's other business or is, in itself, a major enterprise for profit. (14CFR1) (FAA2)
Commercial Passengers	Number of revenue and non-revenue passengers arriving or departing via commercial aircraft and helicopters on a scheduled or non-scheduled flight. (ACI1)
Commercial Pilot	A commercial pilot may act as pilot-in-command of an aircraft carrying passengers for compensation or hire and act as pilot-in-command in an aircraft that is being operated for compensation or hire. (FAA2)
Commercial Rental Motor Vehicle	A motor vehicle obtained from a commercial source such as Military Traffic Management Command (MTMC) rental car agreements for a period of 60 days or less. (GSA2)
Commercial Sector	As defined economically, consists of business establishments that are not engaged in transportation or in manufacturing or other types of industrial activity (agriculture, mining, or construction). Commercial establishments include hotels, motels, restaurants, wholesale businesses, retail stores, laundries, and other service enterprises; religious and nonprofit organizations; health, social, and educational institutions; and Federal, State, and local governments. Street lights, pumps, bridges, and public services are also included if the establishment operating them is considered commercial. (DOE3)
Commercial Service Airport	Airport receiving scheduled passenger service and having 2,500 or more enplaned passengers per year.
Commercial Service Non-Primary Airport	A commercial service airport which is determined by the Secretary [of Transportation] to enplane between 2,500 and 10,000 passengers annually. (FAA11)
Commercial Service Primary Airport	A commercial service airport which is determined by the Secretary [of Transportation] to have more than 10,000 passengers enplaned annually. A primary airport can be further classified as a large, medium, small, or non-hub. (FAA11)
Commercial Vehicle Information Systems and Networks	Commercial Vehicle Information Systems and Networks (CVISN), a national program administered by the Federal Motor Carrier Safety Administration designed to improve motor carrier safety and to enhance the efficiency of administrative processes for industry and government.
Commissioned Agent	An agent who wholesales or retails a refined petroleum product under a commission arrangement. The agent does not take title to the product or establish the selling price, but receives a percentage of fixed fee for serving as an agent. (DOE5)
Commodity	See also Cargo, Freight, Goods, Product.
Commodity Classes	The primary commodities involved in waterways transportation fuels, chemicals, grains and metals. (TNDOT1)
Common Carrier	Any carrier engaged in the interstate transportation of persons/ property on a regular schedule at published rates, whose services are for hire to the general public.
Common Instrument Flight Rules (IFR) Room	A highly automated terminal radar control facility. It provides terminal radar service in an area encompassing more than one major airport that accommodates instrument flight rule (IFR) operations. (FAA14)
Common Point	A significant point over which two or more aircraft will report passing or have reported passing before proceeding on the same or diverging tracks. To establish/maintain longitudinal separation, a controller may determine a common point not originally in the aircraft's flight plan and then clear the aircraft to fly over the point. (FAA4)
Common Return Circuit	A term applied where one wire is used for the return of more than one electric circuit. (49CFR236)
Common Route	That segment of a North American Route between the inland navigation facility and the coastal fix. (FAA4)
Common Traffic Advisory Frequency (CTAF)	A frequency designed for the purpose of carrying out airport advisory practices while operating to or from an airport without an operating control tower. The CTAF may be a UNICOM, Multicom, F99, or I tower frequency and is identified in appropriate aeronautical publications. (FAA4)
Community	A city, group of cities, or a Standard Metropolitan Statistical Area receiving scheduled air service by a certificated route air carrier. (FAA15)
Commutation Ticket	In rail systems, a ticket sold at a reduced rate for a fixed or unlimited number of trips in a designated area during a specified time period. (TRB1)
Commute	Regular travel between home and a fixed location (e.g., work, school). (TRB1)
Commuter	A person who travels regularly between home and work or school. (APTA1)
Commuter Air Carrier	Different definitions are used for safety purposes and for economic regulations and reporting. For safety analysis, commuter carriers are defined as air carriers operating under 14 CFR 135 that carry passengers for hire or compensation on at least five round trips per week on at least one route between two or more points according to published flight schedules, which specify the times, days of the week, and points of service. On March 20, 1997, the size of the aircraft subject to 14 CFR 135 was reduced from 30 to fewer than 10 passenger seats. (Larger aircraft are subject to the more stringent regulations of 14 CFR 121.) Helicopters carrying passengers or cargo for hire, however, are regulated under CFR 135 whatever their size. Although, in practice, most commuter air carriers operate aircraft that are regulated for safety purposes under 14 CFR 135 and most aircraft that are regulated under 14 CFR 135 are operated by commuter air carriers, this is not necessarily the case. For economic regulations and reporting requirements, commuter air carriers are those carriers that operate aircraft of 60 or fewer seats or a maximum payload capacity of 18,000 pounds or less. These carriers hold a certificate issued under section 298C of the Federal Aviation Act of 1958, as amended.
Commuter Authority	Any state, local, regional authority, corporation, or other entity established for purposes of providing commuter rail transportation (including, but not necessarily limited to, the New York Metropolitan Transportation Authority, the Connecticut Department of Transportation, the Maryland Department of Transportation, the Southeastern Pennsylvania Transportation Authority, the New Jersey Transit Corporation, the Massachusetts Bay Transportation Authority, the Port Authority Trans-Hudson Corporation, and any successor agencies) and any entity created by one or more such agencies for the purposes of operating, or contracting for the operation of, commuter rail transportation (49CFR37)
Commuter Bus Service	Fixed route bus service, characterized by service predominantly in one direction during peak periods, limited stops, use of multi-ride tickets, and routes of extended length, usually between the central business district and outlying suburbs. Commuter bus service may also include other service, characterized by a limited route structure, limited stops, and a coordinated relationship to another mode of transportation. (49CFR37)
Commuter Lane	Another name for "High-Occupancy Vehicle Lane." (APTA1)
Commuter Rail	Long-haul passenger service operating between metropolitan and suburban areas, whether within or across the geographical boundaries of a state, usually characterized by reduced fares for multiple rides, and commutation tickets for regular, recurring riders. (FTA1)
Commuter Rail (Transit)	Urban passenger train service for short-distance travel between a central city and adjacent suburb. Does not include rapid rail transit or light rail service.
Commuter Rail Car	A rail passenger car obtained by a commuter authority for use in commuter rail transportation. (49CFR37)
Commuter Rail Locomotives	Commuter rail vehicles used to pull or push commuter rail passenger coaches. Locomotives do not carry passengers themselves. (FTA1)
Commuter Rail Passenger Coaches	Commuter rail passenger vehicles not independently propelled and requiring one or more locomotives for propulsion. (FTA1)
Commuter Rail Self Propelled Passenger Cars	Commuter rail passenger vehicles not requiring a separate locomotive for propulsion. (FTA1)
Commuter Rail Transportation	Short-haul rail passenger service operating in metropolitan and suburban areas, whether within or across the geographical boundaries of a state, usually characterized by reduced fare, multiple ride, and commutation tickets and by morning and evening peak period operations. This term does not include light or rapid rail transportation. (49CFR37)
Commuter Railroad	Those portions of mainline railroad (not electric railway) transportation operations which encompass urban passenger train service for local travel between a central city and adjacent suburbs. Commuter railroad service using both locomotive hauled and self-propelled railroad passenger cars is characterized by multi-trip tickets, specific station-to-station fares, and usually only one or two stations in the central business district. Also known as suburban railroad. (DOE6)
Commuter Train	A short haul passenger train operating on track which is part of the general railroad system of transportation, within an urban, suburban or metropolitan area. It includes a passenger train provided by an instrumentality of a State or political subdivision thereof. (49CFR221)
Commuter Trains	Includes commuter trains and passenger trains other than elevated trains and subways. Includes local and commuter train service. Does not include intercity service by Amtrak. (FHWA3)
Company Automotive Outlet	Any retail outlet selling motor fuel under a reporting company brand name. 1) Company operated. A company retail outlet which is operated by salaried or commissioned personnel paid by the reporting company. 2) Lessee. An independent marketer who leases t
Company Outlet	Any retail outlet (e.g., service station) selling gasoline or diesel fuel that has the ability to set the retail product price and directly collect all or part of the retail margin. This category includes retail outlets 1) being operated by salaried employees of the company and/or its subsidiaries and affiliates, and/or 2) involving personnel services contracted by the company. (DOE5)
Compass Calibration Pad	An airport facility used for calibrating an aircraft compass. (FAA12)
Compass Locator	(See also Middle Marker, Outer Marker) A low power, low or medium frequency (L/MF) radio beacon installed at the site of the outer or middle marker of an instrument landing system (ILS). It can be used for navigation at distances of approximately 16 miles or as authorized in the approach procedure. (FAA4)
Compass Rose	A circle, graduated in degrees, printed on some charts or marked on the ground at an airport. It is used as a reference to either true or magnetic direction. (FAA4)
Compatibility Group Letter	A designated alphabetical letter used to categorize different types of explosive substances and articles for purposes of stowage and segregation. (49CFR171)
Compatible or Compatibility	In relation to State laws and regulations pertaining to commercial motor vehicle safety, having the same effect as the Federal Motor Carrier Safety Regulations (FMCSR) or Federal Hazardous Materials Regulations (FHMR) in that those State rules are either identical or fall within the tolerance guidelines in appendix C, 49CFR350. (49CFR350)
Competent Authority	A national agency responsible under its national law for the control or regulation of a particular aspect of the transportation of hazardous materials (dangerous goods). The term Appropriate Authority, as used in the International Civil Aviation Organization (ICAO) Technical Instructions, has the same meaning as Competent Authority. For purposes of this subchapter, the Associate Administrator [of the Research and Special Programs Administration (RSPA)] for Hazardous Materials Safety is the Competent Authority for the United States. (49CFR171)
Completion	The installation of permanent equipment for the production of oil or gas. If a well is equipped to produce only oil or gas from one zone or reservoir, the definition of a well (classified as an oil well or gas well) and the definition of a completion are identical. However, if a well is equipped to produce oil and/or gas separately from more than one reservoir, a well is not synonymous with a completion. (DOE3)
Component	Any part, or system of parts functioning as a unit, including, but not limited to, piping, processing equipment, containers, control devices, impounding systems, lighting, security devices, fire control equipment, and communication equipment, whose integrity or reliability is necessary to maintain safety in controlling, processing, or containing a hazardous fluid. (49CFR193)
Composite Flight Plan	A flight plan which specifies Visual Flight Rules (VFR) operation for one portion of flight and Instrument Flight Rules (IFR) for another portion. It is used primarily in military operations. (FAA4)
Composite Packaging	A packaging consisting of an outer packaging and an inner receptacle, so constructed that the inner receptacle and the outer packaging form an integral packaging. Once assembled it remains thereafter an integrated single unit; it is filled, stored, shipped and emptied as such. (49CFR171)
Composite Route System	An organized oceanic route structure, incorporating reduced lateral spacing between routes, in which composite separation is authorized. (FAA4)
Composite Separation	A method of separating aircraft in a composite route system where, by management of route and altitude assignments, a combination of half the lateral minimum specified for the area concerned and half the vertical minimum is applied. (FAA4)
Comprehensive Transportation	See Intermodalism Definition No. 3.
Compressed Natural Gas	Natural gas compressed to a volume and density that is practical as a portable fuel supply. It is used as a fuel for natural gas-powered vehicles.
Compressed Natural Gas (CNG)	Natural gas which is comprised primarily of methane, compressed to a pressure at or above 2,400 pounds per square inch and stored in special high-pressure containers. It is used as a fuel for natural gas powered vehicles. (DOE5)
Compression Ratio	The volume of the combustion chamber and cylinder when the piston is at the bottom of its stroke, divided by the volume of the combustion chamber when the piston is at the top of its stroke. (TII1) (TII2)
Compulsory Reporting Points	Reporting points which must be reported to Air Traffic Control (ATC). They are designated on aeronautical charts by solid triangles or filed in a flight plan as fixes selected to define direct routes. These points are geographical locations which are defined by navigation aids/fixes. Pilots should discontinue position reporting over compulsory reporting points when informed by (ATC) that their aircraft is in "radar contact". (FAA4)
Conference	An association of ship owners operating in the same trade route who operate under collective conditions and agree on tariff rates. (MARAD2)
Conflict Alert	(See also Mode C Intruder Alert) A function of certain air traffic control automated systems designed to alert radar controllers to existing or pending situations between tracked targets that require immediate attention/action. (FAA4)
Conflict Resolution	The resolution of potential conflictions between aircraft that are radar identified and in communication with Air Traffic Control (ATC) by ensuring that radar targets do not touch. Pertinent traffic advisories shall be issued when this procedure is applied. Note This procedure shall not be provided utilizing mosaic radar systems. (FAA4)
Conflicting Movement	Movements over conflicting routes. (49CFR236)
Conflicting Routes	Two or more routes, opposing, converging or intersecting, over which movements cannot be made simultaneously without possibility of collision. (49CFR236)
Conformity	Process to assess the compliance of any transportation plan, program, or project with air quality implementation plans. The conformity process is defined by the Clean Air Act.
Congestion Management System (CMS)	Systematic process for managing congestion. Provides information on transportation system performance and finds alternative ways to alleviate congestion and enhance the mobility of people and goods, to levels that meet state and local needs.
Congestion Mitigation & Air Quality Improvement Program (CMAQ)	A categorical Federal-aid funding program created with the ISTEA. Directs funding to projects that contribute to meeting National air quality standards. CMAQ funds generally may not be used for projects that result in the construction of new capacity available to SOVs (single-occupant vehicles).
Consignee	A person or company to whom commodities are shipped. Officially, the legal owner of the cargo. (MARAD2)
Consignee Mark	A symbol placed on packages for export identification purposes; generally consisting of a triangle, square, circle, diamond, or cross, with letters and/or numbers as well as port of discharge. (TNDOT1)
Consignment	The physical transfer of goods from a seller (the consignor), who retains title, to the consignee, who acts as selling agent by selling the goods for commission, remitting the net proceeds to the consignor. (TNDOT1)
Consignor	A person or company shown on the bill of lading as the shipper. (MARAD2)
Consist	On-track railroad equipment such as a train, locomotive, group of railcars, or a single railcar not coupled to another car or to a locomotive. (FRA3)
Consist Responsibility	The railroad employing the crew members operating the consist at time of the accident determines the consist owner for reporting purposes only. (FRA2)
Consolan	A low frequency, long-distance NAVAID used principally for transoceanic navigation. (FAA4)
Consolidated Metropolitan Statistical Area (CMSA)	A metropolitan complex of 1 million or more population, containing two or more component parts designated as primary metropolitan statistical areas (PMSAs). (FHWA3)
Consolidated Vehicle	A vehicle transferred, with or without reimbursement, to General Services Administration (GSA) by another government agency for participating in the Introductory Fleet Management System (IFMS). (GSA2)
Constant Dollars	Dollar value adjusted for changes in the average price level by dividing a current dollar amount by a price index. See also Chained Dollar and Current Dollar.
Construction Pipeline	The various stages involved in the acquisition of a nuclear reactor by a utility. The events that define these stages are the ordering of a reactor, the licensing process, and the physical construction of the nuclear generating unit. A reactor is said to be "in the pipeline" when the reactor is ordered and "out of the pipeline" when it completes low-power testing and begins operation toward full power. (DOE5)
Construction/Maintenance Zone	An area, usually marked by signs, barricades, or other devices indicating that highway construction or highway maintenance activities are ongoing. (NHTSA3)
Consular Invoice	An invoice covering a shipment of export goods certified by a consular official of the country of destination. The invoice shows the value of the shipment in the currency of the country of export. It is used by customs officials of the country of entry to verify the value, quantity, and nature of the shipment. (TNDOT1)
Consumer Commodity	A material that is packaged and distributed in a form intended or suitable for sale through retail sales agencies or instrumentalities for consumption by individuals for purposes of personal care or household use. This term also includes drugs and medicines. (49CFR171)
Consumer Complaint	Oral or written communication from a consumer indicating a possible problem with a product. (USCG1)
Consumer Price Index (CPI)	An index issued by the U.S. Department of Labor, Bureau of Labor Statistics. The CPI is designed to measure changes in the prices of goods and services bought by wage earners and clerical workers in urban areas. It represents the cost of a typical consumption bundle at current prices as a ratio to its cost at a base year. (DOE6)
Consumer Product Safety Act	Establishes the Consumer Product Safety Commission. Definition of consumer product does not include boats which are covered under the statutes. (USCG1)
Consumption Unit Value	Total price per specified unit, including all taxes, at the point of consumption. (DOE5)
Contact	1) Establish communication with (followed by the name of the facility and, if appropriate, the frequency to be used). 2) A flight condition wherein the pilot ascertains the attitude of his aircraft and navigates by visual reference to the surface. (FAA4)
Contact Approach	An approach wherein an aircraft on an Instrument Flight Rules (IFR) flight plan, having an air traffic control authorization, operating clear of clouds with at least 1 mile flight visibility and a reasonable expectation of continuing to the destination airport in those conditions, may deviate from the instrument approach procedure and proceed to the destination airport by visual reference to the surface. This approach will only be authorized when requested by the pilot and the reported ground visibility at the destination airport is at least 1 statute mile. (FAA4)
Container	A large, standard sized metal box into which cargo is packed for shipment; con­tainers are designed to be moved with common handling equipment, functioning as the transfer unit between modes rather than the cargo itself.
Container Cargo	The tonnes of containerized cargo assessed at the Container rate of tools as defined in the St. Lawrence Seaway Tariff of Tolls. (SLSDC1)
Container Chassis	A semitrailer of skeleton construction limited to a bottom frame, one or more axles, specially built and fitted with locking devices for the transport of cargo containers, so that when the chassis and container are assembled, the units serve the same function as an over the road trailer. (49CFR393)
Container Load	A load sufficient in size to fill a container either by cubic measurement or by weight. (MARAD2)
Container on Flatcar (COFC)	Containers resting on railway flatcars without a chassis underneath.
Container On Flatcar (COFC)	This is accomplished with containers resting on railway flatcars. (MARAD1)
Container Terminal	An area designated for the stowage of cargoes in container; usually accessible by truck, railroad and marine transportation. Here containers are picked up, dropped off, maintained and housed. (MARAD2)
Containerization	Stowage of general or special cargoes in a container for transport in the various modes. (MARAD2)
Containerized Cargo	Cargo that is transported in containers that can be transferred easily from one transportation mode to another
Containership	A cargo vessel designed and constructed to transport, within specifically designed cells, portable tanks and freight containers which are lifted on and off with their contents intact. (49CFR171)
Conterminous U.S.	The 48 adjoining States and the District of Columbia. (FAA4)
Continent	One of the large, unbroken masses of land into which the Earth's surface is divided. (DOI4)
Continuous Discharge Capacity	Measured as percent of rated energy capacity. Energy delivered in a constant power discharge required by an electric vehicle for hill climbing and/or high-speed cruise, specified as the percent of its rated energy capacity delivered in a one hour constant-power discharge. (DOE6)
Contract Authority (CA)	A form of Budget Authority that permits obligations to be made in advance of appropriations. Most of the programs under the Federal-Aid Highway Program operate under Contract Authority.
Contract Carrier	Carrier engaged in interstate transportation of persons/ property by motor vehicle on a for-hire basis, but under continuing contract with one or a limited number of cus­tomers to meet specific needs.
Contract Demand	The level of service in terms of the maximum daily and/or annual volumes of natural gas sold and/or moved by the pipeline company to the customer holding the contract. Failure of a pipeline company to provide service at the level of the contract demand specified in the contract can result in a liability for the pipeline company. (DOE1)
Contracted Gas	Any gas for which Interstate Pipeline has a contract to purchase from any domestic or foreign source that cannot be identified to a specific field or group. This includes tailgate plant purchases, single meter point purchases, pipeline purchases, natural gas imports, SNG purchases, and LNG purchases. (DOE5)
Contractor Employee	A person employed by a contractor hired by a railroad to perform normal maintenance work to railroad rolling stock, track structure, bridges, buildings, etc. (FRA2) (FRA3)
Contraflow Lane	Reserved lane for buses on which the direction of bus traffic is opposite to the flow of traffic on the other lanes. (APTA1)
Control Area	(As it pertains to the Interstate Highway System) A metropolitan area, city or industrial center, a topographic feature such as a major mountain pass, a favorable location for a major river crossing, a road hub which would result in material traffic increments on the Interstate route, a place on the boundary between two States agreed to by the States concerned, or other similar point of significance. (23CFR470)
Control Cab Locomotive	A locomotive without propelling motors but with one or more control stands. (49CFR229)
Control Circuit	An electrical circuit between a source of electric energy and a device which it operates. (49CFR236)
Control Machine	An assemblage of manually operated devices for controlling the functions of a traffic control system; it may include a track diagram with indication lights. (49CFR236)
Control Operator	An employee assigned to operate the control machine of a traffic control system. (49CFR236)
Control Sector	An airspace area of defined horizontal and vertical dimensions for which a controller or group of controllers has air traffic control responsibility, normally within an air route traffic control center or an approach control facility. Sectors are established based on predominant traffic flows, altitude strata, and controller workload. Pilot-communications during operations within a sector are normally maintained on discrete frequencies assigned to the sector. (FAA4)
Control Slash	A radar beacon slash representing the actual position of the associated aircraft. Normally, the control slash is the one closest to the interrogating radar beacon site. When Air Route Traffic Control Center (ARTCC) radar is operating in narrow band (digitized) mode, the control slash is converted to a target symbol. (FAA4)
Control Station	The place where the control machine of a traffic control system is located. (49CFR236)
Control Strategy Implementation Plan Revision	The implementation plan which contains specific strategies for controlling the emissions of and reducing ambient levels of pollutants in order to satisfy CAA requirements for demonstrations of reasonable further progress and attainment (including implementation plan revisions submitted to satisfy CAA sections 172(c), 182(b)(1), 182(c)(2)(A), 182(c)(2)(B), 187(a)(7), 187(g), 189(a)(1)(B), 189(b)(1)(A), and 189(d); sections 192(a) and 192(b), for nitrogen dioxide; and any other applicable CAA provision requiring a demonstration of reasonable further progress or attainment).
Control System	A component, or system of components functioning as a unit, including control valves and sensing, warning, relief, shutdown, and other control devices, which is activated either manually or automatically to establish or maintain the performance of another component. (49CFR193)
Controllable Emergency	An emergency where reasonable and prudent action can prevent harm to people or property. (49CFR193)
Controlled Access Rights-of-Way	(See also Right of Way) Lanes restricted for at least a portion of the day for use by transit vehicles and other high occupancy vehicles (HOV's). Use of controlled access lanes may also be permitted for vehicles preparing to turn. The restriction must be sufficiently enforced so that 95 percent of the vehicles using the lanes during the restricted period are authorized to use them. (FTA1)
Controlled Airspace	An airspace of defined dimensions within which air traffic control service is provided to Instrument Flight Rules (IFR) flights and to Visual Flight Rules (VFR) flights in classification. (14CFR1)
Controlled Departure Time Programs (CDT Programs)	These programs are the flow control process whereby aircraft are held on the ground at the departure airport when delays are projected to occur in either the en route system or the terminal of intended landing. The purpose of these programs is to reduce congestion in the air traffic system or to limit the duration of airborne holding in the arrival center or terminal area. A CDT is a specific departure slot shown on the flight plan as an expected departure clearance time (EDCT). (FAA4)
Controlled Point	A location where signals and/or other functions of a traffic control system are controlled from the control machine. (49CFR236)
Controlled Time of Arrival	The original estimated time of arrival adjusted by the ATCSCC ground delay factor. (FAA4)
Controller	(See also Air Traffic Control Specialist, Final Controller) A person authorized to provide air traffic control services. (FAA4)
Controlling Depth	The least available water in a navigable channel which limits the amount of cargo which may be carried by the vessel. (TNDOT1)
Controlling Locomotive	A locomotive arranged as having the only controls over all electrical, mechanical and pneumatic functions for one or more locomotives, including controls transmitted by radio signals if so equipped. It does not include two or more locomotives coupled in multiple which can be moved from more than one set of locomotive controls. (49CFR218)
Conventional Cab	A cab design in which the engine is located ahead, or mostly ahead, of the cowl. (TII1) (TII2)
Conversion Factor	(See also British Thermal Unit) A number that translates units of one system into corresponding values of another system. Conversion factors can be used to translate physical units of measure for various fuels into British Thermal Unit (BTU) equivalents. (DOE3) (DOE4)
Converter Dolly	A motor vehicle consisting of a chassis equipped with one or more axles, a fifth wheel and/or equivalent mechanism, and drawbar, the attachment of which converts a semitrailer to a full trailer. (49CFR393)
Convertible	A truck or trailer that can be used either as a flatbed or open-top by removing side panels. (ATA1)
Coordinates	The intersection of lines of reference, usually expressed in degrees/minutes/seconds of latitude and longitude, used to determine position or location. (FAA4)
Coordination Fix	The fix in relation to which facilities will handoff, transfer control of an aircraft, or coordinate flight progress data. For terminal facilities, it may also serve as a clearance for arriving aircraft. (FAA4)
Copter	See Helicopter.
Cordelle	A hawser; a towline such as those used to pull keelboats in the French-speaking parts of North America. (TNDOT1)
Corporate Average Fuel Economy (CAFE) Standards	CAFE standards were originally established by Congress for new automobiles, and later for light trucks, in Title V of the Motor Vehicle Information and Cost Savings Act (15 U.S.C. 1901, et seq.) with subsequent amendments. Under CAFE, automobile manufacturers are required by law to produce vehicle fleets with a composite sales-weighted fuel economy which cannot be lower than the CAFE standards in a given year, or for every vehicle which does not meet the standard, a fine of $5.00 is paid for every one-tenth of a mpg below the standard. (DOE6)
Corporate Average Fuel Economy Standards (CAFÉ)	Originally established by Congress for new automobiles and later for light trucks. This law requires automobile manufacturers to produce vehicle fleets with a composite sales-weighted fuel economy not lower than the CAFE standards in a given year. For every vehicle that does not meet the standard, a fine is paid for every one-tenth of a mile per gallon that vehicle falls below the standard.
Corporate/Executive Flying	The use of aircraft owned or leased, and operated by a corporate or business firm for the transportation of personnel or cargo in furtherance of the corporation's or firm's business, and which are flown by compensation for piloting. (NTSB2)
Correction	An error has been made in the transmission and the correct version follows. (FAA4)
Corridor	A broad geographical band that follows a general directional flow connecting major sources of trips that may contain a number of streets, highways and transit route alignments. (APTA1)
Cost, Insurance, Freight (CIF)	A type of sale in which the buyer of the product agrees to pay a unit price that includes the f.o.b. value of the product at the point of origin plus all costs of insurance and transportation. This type of transaction differs from a delivered purchase in that the buyer accepts the quantity as determined at the loading port (as certified by the Bill of Lading and Quality Report) rather than pay on the basis of the quantity and quality ascertained at the unloading port. It is similar to the terms of an f.o.b. sale, except that the seller, as a service for which he is compensated, arranges for transportation and insurance. (DOE3)
Coupled Approach	(See also Autoland Approach) A coupled approach is an instrument approach performed by the aircraft autopilot which is receiving position information and/or steering commands from onboard navigation equipment. In general, coupled nonprecision approaches must be discontinued and flown manually at altitudes lower than 50 feet below the minimum descent altitude, and coupled precision approaches must be flown manually below 50 feet ALG. Note Coupled and autoland approaches are flown in Visual Flight Rules (VFR) and Instrument Flight Rules (IFR). It is common for carriers to require their crews to fly coupled approaches and autoland approaches (if certified) when the weather conditions are less than approximately 4,000 Runway Visual Range (RVR). (FAA4)
Courier Services (Except By Air)	Establishments primarily engaged in the delivery of individually addressed letters, parcels and packages (generally under 100 pounds), except by means of air transportation or by the U.S. Postal Service. (BOC1)
Course	(See also Bearing; Flight Path) 1) The intended direction of flight in the horizontal plane measured in degrees from north. 2) The Instrument Landing System (ILS) localizer signal pattern usually specified as the front course or the back course. 3) The intended track along a straight, curved, or segmented Microwave Landing System (MLS) path. (FAA4)
Coverage Ratios	The ratio used to measure the degree to which expenditures are funded or "covered" by the various types of revenues. This ratio indicates the percent of expenditures that is funded by identifiable transportation-related tax receipts, fees, etc. (BTS3)
Cowboy	Reckless driver. (ATA1)
Cowl	The front part of a cab or body directly below the base of the windshield, between fire wall and instrument panel, and usually including the hood. (TII1) (TII2)
Crack	A fracture without complete separation into parts, except that castings with shrinkage cracks or hot tears that do not significantly diminish the strength of the member are not considered to be cracked. (49CFR229)
Crane	A mechanical handling device used for lifting and moving heavy items. (MARAD1)
Crash	See also Accident, Casualty, Collision, Derailment, Fatality, Event, Hit and Run, Incident, Injury, Vehicle Maneuver, Vehicle Role.
Crash (Highway)	An event that produces injury and/or property damage, involves a motor vehicle in transport, and occurs on a trafficway or while the vehicle is still in motion after running off the trafficway.
Crash Severity	The most severe injury sustained in the crash as recorded on the police accident report Property Damage Only (no injuries), Minor or Moderate (Evident, but not incapacitating; complaint of injury; or injured, severity unknown), Severe or Fatal (killed or incapacitating). (NHTSA1)
Crash Type	Single vehicle or multiple vehicle crash. (NHTSA3)
Creeper Gear	Lowest gear or combination of gears used for extra power. Also known as Grandma. (ATA1)
Crest of Flood	Rise in river has reached its peak. (TNDOT1)
Crevasse	A deep fissure in snow or ice. (DOI4)
Crevasse Field	An area of deep fissures in the surface of an ice mass caused by breaking or parting. (DOI3)
Crewmember	A person assigned to perform duty in an aircraft during flight time. (14CFR1) (49CFR171)
Crib	A crate like construction of logs or beams, usually filled with stones, placed in water as a free standing mooring device or as the foundation of a pier or wharf. (DOI4)
Crib Area	Containing one or more cribs, (frames of logs or beams filled with heavy material that are sunk and used as foundations or retaining walls for docks, piers or similar structures, or as supports for pipelines). (DOI3)
Critical Altitude	The maximum altitude at which, in standard atmosphere, it is possible to maintain, a specified power or a specified manifold pressure at a specified rotational speed. Unless otherwise stated, the critical altitude is the maximum altitude at which it is possible to maintain, at the maximum continuous rotational speed, one of the following 1) The maximum continuous power, in the case of engines for which this power rating is the same at sea level and at the rated altitude; 2) The maximum continuous rated manifold pressure, in the case of engines, the maximum continuous power of which is governed by a constant manifold pressure. (14CFR1)
Critical Engine	The engine whose failure would most adversely affect the performance or handling qualities of an aircraft. (14CFR1) (FAA4)
Cross (Fix) At (Altitude)	Used by Air Traffic Control (ATC) when a specific altitude restriction at a specified fix is required. (FAA4)
Cross (Fix) At or Above (Altitude)	Used by Air Traffic Control (ATC) when an altitude restriction at a specified fix is required. It does not prohibit the aircraft from crossing the fix at a higher altitude than specified; however, the higher altitude may not be one that will violate a succeeding altitude restriction or altitude assignment. (FAA4)
Cross (Fix) At or Below (Altitude)	Used by Air Traffic Control (ATC) when a maximum crossing altitude at a specific fix is required. It does not prohibit the aircraft from crossing the fix at a lower altitude; however, it must be at or above the minimum Instrument Flight Rules (IFR) altitude. (FAA4)
Cross Protection	An arrangement to prevent the improper operation of a signal, switch, movable-point frog, or derail as the result of a cross in electrical circuits. (49CFR236)
Crossboard	A simple type of daymark in the shape of a "X" formerly used extensively on the Missouri River only. (TNDOT1)
Crosscurrent	Stream flow across navigable portion of river. (TNDOT1)
Crossing	A place where a channel moves from along one bank of the river over to the other bank of the river. (TNDOT1)
Crossing Daymark	A diamond-shaped daymark erected at the head and foot of crossings and used by pilots to steer on. (TNDOT1)
Crossing Light	A light located at the head and foot of crossings used by pilots to steer on; may be equipped with an additional high intensity directional light. (TNDOT1)
Cross-Servicing	Petroleum products, repairs, supplies, and services provided to General Services Administration (GSA) by other Federal agencies, or vice versa. Cross servicing may also refer to commercial firms where GSA or other Federal agencies have agreements with these firms to supply services repairs, or fuel. (GSA2)
Crosstie	The transverse member of the track structure to which the rails are fastened. Its function is to provide proper gauge and to cushion, distribute, and transmit the stresses of traffic through the ballast to the roadbed. (TRB1)
Crosstown	Non-radial bus or rail service which does not enter the Central Business District (CBD). (APTA1)
Crosswind	1) When used concerning the traffic pattern, the word means "crosswind leg." 2) When used concerning wind conditions, the word means a wind not parallel to the runway or the path of an aircraft. (FAA4)
Crosswind Component	The wind component measured in knots at 90 degrees to the longitudinal axis of the runway. (FAA4)
Crude Oil	A mixture of hydrocarbons that exists in the liquid phase in natural underground reservoirs and remains liquid at atmospheric pressure after passing through surface-separating facilities.
Crude Oil Imports	The volume of crude oil imported into the 50 States and the District of Columbia, including imports from U.S. territories, but excluding imports of crude oil into the Hawaiian Foreign Trade Zone. (DOE6)
Crude Oil Petroleum	A naturally occurring, oily, flammable liquid composed principally of hydrocarbons. Crude oil is occasionally found in springs or pools but usually is drilled from wells beneath the earth's surface. (DOE5)
Crude Oil Production	The volume of crude oil produced from oil reservoirs during given periods of time. The amount of such production for a given period is measured as volumes delivered from lease storage tanks (i.e., the point of custody transfer) to pipelines, trucks, or other media for transport to refineries or terminals with adjustments for 1) net differences between opening and closing lease inventories, and 2) basic sediment and water (BS&W). (DOE5)
Cruise	(See also Instrument Approach Procedure) Used in an Air Traffic Control (ATC) clearance to authorize a pilot to conduct flight at any altitude from the minimum Instrument Flight Rules (IFR) altitude up to and including the altitude specified in the clearance. The pilot may level off at any intermediate altitude within this block of airspace. Climb/descent within the block is to be made at the discretion of the pilot. However, once the pilot starts descent and verbally reports leaving an altitude in the block, he may not return to that altitude without additional ATC clearance. Further, it is approval for the pilot to proceed to and make an approach at destination airport and can be used in conjunction with: 1) An airport clearance limit at locations with a standard special instrument approach procedure. The Federal Aviation Regulations (FAR) require that if an instrument letdown to an airport is necessary, the pilot shall make the letdown in accordance with a standard/special instrument approach procedure for that airport, or 2) An airport clearance limit at locations that are within/below/outside controlled airspace and without a standard/special instrument approach procedure. Such a clearance is NOT AUTHORIZATION for the pilot to descend under Instrument Flight Rules (IFR) conditions below the applicable minimum IFR altitude nor does it imply that ATC is exercising control over aircraft in Class G airspace; however, it provides a means for the aircraft to proceed to destination airport, descend, and land in accordance with applicable FAR's governing Visual Flight Rules (VFR) flight operations. Also, this provides search and rescue protection until such time as the IFR Right plan is closed. (FAA4)
Cruise Climb	A climb technique employed by aircraft, usually at a constant power setting, resulting in an increase of altitude as the aircraft weight decreases. (FAA4)
Cruising	Proceeding normally, unrestricted, with an absence of drastic rudder or engine changes. (USCG2)
Cruising Altitude	An altitude or Right level maintained during en route level flight. This is a constant altitude and should not be confused with a cruise clearance. (FAA4)
Cruising Level	A level maintained during a significant portion of a flight. (FAA4)
Cubic Foot	Conversion equivalents 1,728 cubic inches, 60 pints, 8/10 bushel, 0.028 cubic meter, 28.32 liters. (TNDOT1)
Cubic Inch Displacement (CID)	A measure of the physical size of the engine. (BOC3)
Cul-De-Sac	The round or circular section of the end of a dead-end street. (DOI3)
Curb Weight	The weight of a motor vehicle with standard equipment, maximum capacity of fuel, oil, and coolant and, if so equipped, air conditioning and additional weight of optional engine. Curb weight does not include the driver. (49CFR393) (49CFR571)
Current	See Drift.
Current Assets	Cash and cash equivalents, as well as current receivables and short-term investments, deposits and inventories. (BTS4)
Current Dollars	Dollar value of a good or service in terms of prices current at the time the good or service is sold. See also Chained Dollar and Constant Dollar.
Current Flight Plan	The flight plan, including changes, if any, brought about by subsequent clearances. (FAA4)
Current Liabilities	Current portion of long-term debt and of capital leases, air travel liabilities and other short-term trade accounts payable. (BTS4)
Current of Traffic	The movement of trains on a specified track in a designated direction. (49CFR236)
Custom House	The government office where duties and/or tolls are placed on imports or exports and are paid on vehicles or vessels entered or cleared. (TNDOT1)
Customs	Duties, tolls, or taxes imposed by a government on commodities imported into or exported from that country. (TNDOT1)
Customs House Broker	(See also Broker; Freight Forwarder) A person licensed by the Treasury Department to transact business at a customhouse on behalf of other persons. (TNDOT1)
Customs Tariff	A schedule of charges assessed by the federal government on imported and/or exported goods. (TNDOT1)
Cut	An excavation of the Earth's surface to provide passage for a road, railway, canal, etc. (DOI4)
Cut Her Loose	To untie all lines. (TNDOT1)
Cut-In Circuit	A roadway circuit at the entrance to automatic train stop, train control or cab signal territory by means of which locomotive equipment of the continuous inductive type is actuated so as to be in operative condition. (49CFR236)
Cutoff	A cut made by dredging that eliminates a bend in the river or curve. Usually refers to a new channel made by entering at the head of a bend, passing through the cut, and emerging at the end of the bend on the downstream side. (TNDOT1)
Cut-Section	A location other than a signal location where two adjoining track circuits end within a block. (49CFR236)
Cylinder	A pressure vessel designed for pressures higher than 40 psi and having a circular cross section. It does not include a portable tank, multi-unit car tank, cargo tank, or tank car. (49CFR171)
Daily Average Flow	The volume of gas that moves through a section of pipe determined by dividing the total annual volume of gas that moves through a section of pipe by 365 days. Volumes are expressed in million cubic feet per day measured at a pressure of 14.73 psia and a temperature of 60 degrees Fahrenheit. For pipes that operate with bidirectional flow, the volume used in computing the average daily flow rate is the volume associated with the direction of flowing gas on the peak day. (DOE1)
Daily Vehicle Travel	Is the amount of vehicle travel (in thousands) accumulated over a 24-hour day, midnight to midnight, traversed along a "public road" by motorized vehicles, excluding construction equipment or farm tractors. Vehicle travel not occurring on public roads, such as that occurring on private land roads (private roads in parking lots, shopping centers, etc.) must be also be excluded. (FHWA2)
Dam	A barrier constructed across a watercourse to control the flow or raise the level of water. (DOI4)
Dam Bulletin Board	A bulletin board located at certain dams to give stage readings and indicate whether to use lock or go over the dam. "N.P." means use the lock. "P" means go over the dam. Largely obsolete in use since the advent of radio communications. (TNDOT1)
Dam Open	The situation when the gates are open so as to pass water unimpeded. (TNDOT1)
Dam Warning Buoys	Buoys placed above the face of a dam to warn traffic of danger. These buoys may be of peculiar shape and generally have the word "danger" posted on them. (TNDOT1)
Dam/Weir	A barrier constructed to control the flow or raise the level of water. (DOI3)
Danger Area	An airspace of defined dimensions within which activities dangerous to the flight of aircraft may exist at specified times. Note The term "Danger Area" is not used in reference to areas within the United States or any of its possessions or territories. (FAA4)
Danger Signal	Four or more short blasts of the boat's or lockmaster's whistle to indicate danger or the need for special caution. (TNDOT1)
Datum	Reference point for elevations of structures and water level. (TNDOT1)
Day	From 6 a.m. to 5:59 p.m. (NHTSA3)
Daymark	An unlighted shore aid to navigation, either diamond, square, or triangle shaped. (TNDOT1)
Dead Axle	Non powered rear axle on tandem truck or tractor. (ATA1)
Dead Freight	The freight charges paid by the charterer of a vessel for contracted space which is left partially unoccupied. (TNDOT1)
Dead Heading	Running empty. (ATA1)
Dead Locomotive	A locomotive other than a control cab locomotive that does not have any traction device supplying tractive power; or a control cab locomotive that has a locked and unoccupied cab. (49CFR229)
Dead Reckoning	As applied to flying, the navigation of an airplane solely by means of computations based on airspeed, course, heading, wind direction, speed, groundspeed, and elapsed time. (FAA4)
Dead Section	A section of track, either within a track circuit or between two track circuits, the rails of which are not part of a track circuit. (49CFR236)
Deadhead	1) Any water-soaked wooden pile, tree, or log that is floating just awash in a nearly vertical position. A menace to small boats and to the propellers of vessels. 2) A tow returning from a trip without barges or with empty barges. (TNDOT1)
Deadhead Shipment	Commonly-used description of an empty backhaul.
Deadhead Transportation	Occurs when an employee is traveling at the direction or authorization of the carrier to or from an assignment, or the employee is involved with a means of conveyance furnished by the carrier or compensated for by the carrier. (FRA2)
Deadman Control	A pedal, handle, or other form of switch, or combination thereof, that the operator must keep in a depressed or twisted position while a rail vehicle (or train) is moving. If the control is released, the power is cut off and the brakes are applied. (TRB1)
Deadweight Tonnage (Water)	The carrying capacity of a vessel in long tons (2,240 pounds). It is the difference between the number of tons of water a vessel displaces “light” and the number of tons it displaces when submerged to the “load line.”
Deadweight Tons	The lifting capacity of a ship expressed in long tons (2,240 lbs.), including cargo, commodities, and crew. (DOE5)
Decision Height (DH) (DH)	With respect to the operation of aircraft, means the height at which a decision must be made, during an Instrument Landing System (ILS) or Precision Approach Radar (PAR) instrument approach, to either continue the approach or to execute a missed approach. (14CFR1)
Deck Plate	A horizontal surface designed to provide a person with stable footing for the performance of work such as the connection and disconnection of air and electrical lines, gaining access to permanently-mounted equipment or machinery or for similar needs. (49CFR399)
Decoder	(See also Code; Discrete Code) The device used to decipher signals received from Air Traffic Control Radar Beacon System (ATCRBS) transponders to effect their display as select codes. (FAA4)
Dedicated Funds	Any funds raised specifically for transit purposes and which are dedicated at their source (e.g., sales taxes, gasoline taxes, and property taxes), rather than through an allocation from the pool of general funds. (FTA1)
Dedicated Tow	A single commodity moved from origin to destination by the same towboat without picking up or dropping off other barges. Often used in the movement of grain, coal, and bulk liquid. (TNDOT1)
Deep Sea Domestic Transportation of Freight	Establishments primarily engaged in operating vessels for transportation of freight on the deep seas between ports of the United States, the Panama Canal Zone, Puerto Rico, and United States island possessions or protectorates. (BOC1)
Deep Sea Transportation of Passengers	Establishments primarily engaged in operating vessels for the transportation of passengers on the deep seas except by ferry. (BOC1)
Defect Notification System	A computerized system that enables the Coast Guard to monitor the efforts of boat and equipment manufacturers in complying with 46 U.S.C. 4310. (USCG1)
Defense Visual Flight Rules (DVFR) (DVFR)	Rules applicable to flights within an Air Defense Identification Zone conducted under the visual flight rules in Federal Aviation Regulation, Part 91. (FAA2) (FAA4) (FAA13)
Deferred Credits	Items for which additional information or events are required to determine their ultimate disposition and accounting classification, including deferred taxes, deferred investment tax credits, and other suspense items. (BTS4)
Deferred Income Taxes	Tax effects which are deferred for allocation to income tax expense of future periods. (BTS4)
Deferred Investment Tax Credits	Investment tax credits deferred for amortization over the service life of the related equipment. (BTS4)
Defined Mandatory Use Service Area	That listed in the determination of each Fleet Management Center or Fleet Management Subcenter. (GSA2)
Degree of (Critical) Hazard	A situation in which collision avoidance was due to chance rather than an act on the part of the pilot. Less than 100 feet of aircraft separation would be considered critical. (FAA10)
Degree of (No Hazard) Hazard	A situation in which direction and altitude would have made a midair collision improbable regardless of evasive action taken. (FAA10)
Degree of (Potential) Hazard	An incident which would have resulted in a collision if no action had been taken by either pilot. Closest proximity of less than 500 feet would usually be required in this case. (FAA10)
Delay	Delays are incurred when any action is taken by a controller that prevents an aircraft from proceeding normally to its destination for an interval of 15 minutes or more. This includes actions to delay departing, enroute, or arriving aircraft as well as actions taken to delay aircraft at departing airports due to conditions en route or at destination airports. (FAA3)
Delay Indefinite (Reason If Known) Expect Further Clearance (Time)	Used by Air Traffic Control (ATC) to inform a pilot when an accurate estimate of the delay time and the reason for the delay cannot immediately be determined; (e.g., a disabled aircraft on the runway, terminal or center area saturation, weather below landing minimums, etc). (FAA4)
Delay Time	As applied to an automatic train stop or train control system, the time which elapses after the onboard apparatus detects a more restrictive indication until the brakes start to apply. (49CFR236)
Deliverability	Represents the number of future years during which a pipeline company can meet its annual requirements for its presently certificated delivery capacity from presently committed sources of supply. The availability of gas from these sources of supply shall be governed by the physical capabilities of these sources to deliver gas by the terms of existing gas-purchase contracts, and by limitations imposed by State or Federal regulatory agencies. (DOE5)
Delivered	The physical transfer of natural, synthetic, and/or supplemental gas from facilities operated by the responding company to facilities operated by others or to consumers. (DOE5)
Delivered Energy	The amount of energy delivered to the site (building); no adjustment is made for the fuels consumed to produce electricity or district sources. This is also referred to as net energy. (DOE5)
Demand Air Taxi	Use of an aircraft operating under Federal Aviation Regulations, part 135, passenger and cargo operations, including charter and excluding commuter air carrier. (FAA9)
Demand Response	Non-fixed-route service utilizing vans or buses with passengers boarding and alighting at pre-arranged times at any location within the system's service area. Also called "Dial-a-Ride." (APTA1)
Demand Responsive System	Any system of transporting individuals, including the provision of designated public transportation service by public entities and the provision of transportation service by private entities, including but not limited to specified public transportation service, which is not a fixed route system. (49CFR37)
Demand Responsive Vehicle (Transit)	A nonfixed-route, nonfixed-schedule vehicle that operates in response to calls from passengers or their agents to the transit operator or dispatcher.
Demand-Responsive	Descriptive term for a service type, usually considered paratransit, in which a user can access transportation service that can be variably routed and timed to meet changing needs on an as-needed basis.
Demurrage	In domestic U.S. transportation, a penalty charge against shippers or consignees for delaying the carrier's equipment beyond the allowed free time provision of the tariff at the rail ramp ; in international transportation, a storage charge to shippers which starts accruing after a container is discharged from a vessel. The charge varies according to rules of the appropriate tariff. (MARAD2)
Department of Energy (DOE)	The Department of Energy's overarching mission is to advance the national , economic and energy security of the United States; to promote scientific and technological innovation in support of that mission; and to ensure the environmental cleanup of the national nuclear weapons complex. The Department has four strategic goals toward achieving the mission: Defense Strategic Goal: To protect our national security by applying advanced science and nuclear technology to the Nation’s defense; Energy Strategic Goal: To protect our national and economic security by promoting a diverse supply and delivery of reliable, affordable, and environmentally sound energy; Science Strategic Goal: To protect our national and economic security by providing world-class scientific research capacity and advancing scientific knowledge; and Environment Strategic Goal: To protect the environment by providing a responsible resolution to the environmental legacy of the Cold War and by providing for the permanent disposal of the Nation’s high-level radioactive waste.
Department of Health and Human Services (HHS)	The Department of Health and Human Services is the United States government's principal agency for protecting the health of all Americans and providing essential human services, especially for those who are least able to help themselves.
Department of Housing and Urban Development (HUD)	HUD's mission is to increase homeownership, support community development and increase access to affordable housing free from discrimination. To fulfill this mission, HUD will embrace high standards of ethics, management and accountability and forge new partnerships--particularly with faith-based and community organizations--that leverage resources and improve HUD's ability to be effective on the community level.
Department of Transportation (DOT)	Establishes the nation's overall transportation policy. Under its umbrella there are ten administrations whose jurisdictions include highway planning, development and construction; urban mass transit; railroads; aviation; and the safety of waterways, ports, highways, and oil and gas pipelines. The Department of Transportation (DOT) was established by act of October 15, 1966, as amended (49 U.S.C. 102 and 102 note), "to assure the coordinated, effective administration of the transportation programs of the Federal Government" and to develop "national transportation policies and programs conducive to the provision of fast, safe, efficient, and convenient transportation at the lowest cost consistent therewith." (OFR1)
Departure Angle	The smallest angle, in a plane side view of an automobile, formed by the level surface on which the automobile is standing and a line tangent to the rear tire static loaded radius arc and touching the underside of the automobile rearward of the rear tire. (49CFR523)
Departure Center	The air route traffic control center having jurisdiction for the airspace that generates a flight to the impacted airport. (FAA4)
Departure Control	A function of an approach control facility providing air traffic control service for departing Instrument Flight Rules (IFR) and, under certain conditions, Visual Flight Rules (VFR) aircraft. (FAA4)
Departure Time	The time an aircraft becomes airborne. (FAA4)
Depreciation and Amortization	All depreciation and amortization expenses applicable to owned or leased property and equipment including that categorized as flight equipment or ground property and equipment. (BTS4)
Derailment	A derailment occurs when one or more than one unit of rolling stock equipment leaves the rails during train operations for a cause other than collision, explosion, or fire. (FRA3)
Derailment/Bus Going Off Road	A non-collision incident which occurs as a result of rolling equipment leaving the rail, or buses leaving the roadway, and for roll overs. Report all incidents regardless of severity. (FTA1)
Derailment/Left Roadway	A non-collision incident in which a transit vehicle leaves the rails or road on which it travels. This also includes rollovers. Reports are made for all occurrences. (FTA2)
Deregulation	Revisions or complete elimination of economic regulations controlling transportation. For example, the Motor Carrier Act of 1980 and the Staggers Act of 1980 revised the economic controls over motor carriers and railroads. (MARAD1)
Descent Speed Adjustments	Speed deceleration calculations made to determine an accurate vertex time of arrival (VTA). These calculations start at the transition point and use arrival speed segments to the vertex. (FAA4)
Design Capacity	(See also Certified Capacity) Is the capacity associated with the direction of the flow observed on the peak day. (DOE1)
Design Head	The achieved river, pondage, or reservoir surface height (forebay elevation) that provides the water level to produce the full flow at the gate of the turbine in order to attain the manufacturer's installed nameplate rating for generation capacity. (DOE5)
Design Live Road	The live road that the structure was designed to carry (85 psf, H-10, H-15, and HS-20). (DOI2)
Design Speed	Design speed determines the maximum degree of road curvature and minimum safe stopping, meeting, passing, or intersection sight distance. (DOI2)
Designated Area	The Fleet Management Center location as defined in the applicable determination. (GSA2)
Designated Associated Equipment	Inboard Engine, Outboard Engine, and Stern Drive Unit. Specific equipment, besides completed boats, which has been designated in 33 (CFR) 179.03 as being subject to the requirements of 46 (U.S.C.) 4310. Other items of associated equipment may be the cause for recall of boats, but the manufacturers of those items of associated equipment are not subject to the requirement for recall. (USCG1)
Designated Facility	A hazardous waste treatment, storage, or disposal facility that has been designated on the manifest by the generator. (49CFR171)
Designated Public Transportation	Transportation provided by a public entity (other than public school transportation) by bus, rail, or other conveyance (other than transportation by aircraft or intercity or commuter rail transportation) that provides the general public with general or special service, including charter service, on a regular and continuing basis. (49CFR37)
Designated Seating Capacity	The number of designated seating positions provided. (49CFR571)
Designated Seating Position	Any plan view location capable of accommodating a person at least as large as a 5th percentile adult female, if the overall seat configuration and design and vehicle design is such that the position is likely to be used as a seating position while the vehicle is in motion, except for auxiliary seating accommodations such as temporary or folding jump seats. Any bench or split-bench seat in a passenger car, truck or multipurpose passenger vehicle with a Gross Vehicle Weight Rating (GVWR) less than 10,000 pounds, having greater than 50 inches of hip room (measured in accordance with Society of Automotive Engineers (SAE) Standard J1100a) shall have not less than three designated seating positions, unless the seat design or vehicle design is such that the center position cannot be used for seating. (49CFR571)
Designated Service	Exclusive operation of a locomotive under the following conditions; 1) The locomotive is not used as an independent unit or the controlling unit is a consist of locomotives except when moving for the purpose of servicing or repair within a single yard area; 2) The locomotive is not occupied by operating or deadhead crews outside a single yard area; and 3) The locomotive is stenciled "Designated Service-DO NOT OCCUPY". (49CFR223)
Destination	For travel period trips, the destination is the farthest point of travel from the point of origin of a trip of 75 miles or more one-way. For travel day trips, the destination is the point at which there is a break in travel. (FHWA3)
Determination	A document signed by the Administrator of the General Services Administration, setting forth the decision to establish an Interagency Fleet Management Center at a specific location. (GSA2)
Detresfa (Distress Phase)	The code word used to designate an emergency phase wherein there is reasonable certainty that an aircraft and its occupants are threatened by grave and imminent danger or require immediate assistance. (FAA4)
Devanning	The unloading of a container or cargo van. (MARAD2)
Deviation	1) A departure from a current clearance, such as an off course maneuver to avoid weather or turbulence. 2) Where specifically authorized in the FARs and requested by the pilot, Air Traffic Control (ATC) may permit pilots to deviate from certain regulations. (FAA4)
Dial Up Access Terminal (DUAT)	The capability for direct user access terminals to file flight plans into the National Airspace System (NAS) and access weather information from the National Graphic Weather Display System. (FAA8)
Dial-A-Ride	Term for demand-responsive systems usually delivering door-to-door service to clients, who make request by telephone on an as-needed reservation or subscription basis.
Diesel Fuel	A complex mixture of hydrocarbons with a boiling range between approximately 350 and 650 °F. Diesel fuel is composed primarily of paraffins and naphthenic compounds that auto-ignite from the heat of compression in a diesel engine. Diesel is used primarily by heavy-duty road vehicles, construction equipment, locomotives, and by marine and stationary engines.
Diesel Fuel System	(See also Carburetor, Diesel Fuel, Fuel Injection) Diesel engines are internal combustion engines that burn diesel oil rather than gasoline. Injectors are used to spray droplets of diesel oil into the combustion chambers, at or near the top of the compression stroke. Ignition follows due to the very high temperature of the compressed in-take air, or to the use of "glow plugs," which retain heat from previous ignitions (spark plugs are not used). Diesel engines are generally more fuel efficient than gasoline engines, but must be stronger and heavier due to high compression ratios. (DOE4)
Diesel Fuel, No 1.	A volatile distillate fuel oil with a boiling range between 300 and 575 degrees Fahrenheit and used in high-speed diesel engines generally operated under wide variations in speed and load. Includes type C-B diesel fuel used for city buses and similar operations. Properties are defined in American Society for Testing and Materials (ASTM) Specification D 975. (DOE2)
Diesel Fuel, No 2.	A gas oil type distillate of lower volatility with distillation temperatures at the 90-percent point between 540 and 640 degrees Fahrenheit for use in high speed diesel engines generally operated under uniform speed and load conditions. Includes Type R-R diesel fuel used for railroad locomotive engines, and Type T-T for diesel-engine trucks. Properties are defined in American Society for Testing and Materials (ASTM) Specification D 975. (DOE2)
Diesel-Electric Plant	A generating station that uses diesel engines to drive its electric generators. (DOE5)
Differential	An amount added or deducted from base rate to make a rate to or from some other point or via another route. (MARAD2)
Differential (Standard Type)	The gear assembly on the drive axle that permits the wheels to turn at different speeds; no-slip or limited-slip type a gear assembly on the drive axle that will not permit one wheel to spin while the other is motionless. (TII1) (TII2)
Digital Brite Radar Indicator Tower Equipment (DBRITE)	Alphanumeric display systems for control towers using digital scan converter systems in a radar scope-type presentation. (FAA8)
Dike	(See also Hurdle) A construction, usually of piling or stone and usually at right angles to the current, for the purpose of diverting the river current away from the banks and toward the channel. A dike serves the same purpose as a wingdam. Dike pilings are usually visible at normal water stages but are often submerged in high water and constitute a navigational hazard. (TNDOT1)
Dike Light	A light installed on the end of a dike, normally a portable 90 mm battery-operated light. (TNDOT1)
Dinner Bucket Boat	A boat operating without benefit of a cook house. (TNDOT1)
Direct	Straight line flight between two navigational aids, fixes, points, or any combination thereof. When used by pilots in describing off-airway routes, points defining direct route segments become compulsory reporting points unless the aircraft is under radar contact. (FAA4)
Direct Altitude and Identity Readout System	System is a modification to the AN/TPX42 Interrogator System. The Navy has two adaptations of the DAIR System-Carrier Air Traffic Control Direct Altitude and Identification Readout System for Aircraft Carriers and Radar Air Traffic Control Facility Direct Altitude and Identity Readout System for land-based terminal operations. The DAIR detects, tracks, and predicts secondary radar aircraft targets. Targets are displayed by means of computer-generated symbols and alphanumeric characters depicting flight identification, altitude, ground speed, and Right plan data. The DAIR System is capable of interfacing with ARTCC's. (FAA4)
Direct Assistance	Transportation and other relief services provided by a motor carrier or its driver(s) incident to the immediate restoration of essential services (such as, electricity, medical care, sewer, water, telecommunications, and telecommunication transmissions) or essential supplies (such as, food and fuel). It does not include transportation related to long-term rehabilitation of damaged physical infrastructure or routine commercial deliveries after the initial threat to life and property has passed. (49CFR390)
Direct Funding	Funds transferred directly from the Secretary of the Interior to the ITG upon request for programs contracted or compacted under P.L. 93-638 as amended.
Direct Service Tribes	ITGs that receive services directly from the BIA.
Direct Transit Passengers	Passengers stopping temporarily at a designated airport and departing on an aircraft with the same flight number. They are counted only once. (ACI1)
Direct User Access Terminal System (DUATS)	An automated pilot self-briefing and flight plan filing system. For pilots with access to a computer, modem, and touch telephone, the system provides direct access to a national weather data base and the ability to file flight plans without contact with a flight service station. (FAA14)
Direction Finder (DF)	A radio receiver equipped with a directional sensing antenna used to take bearings on a radio transmitter. Specialized radio direction finders are used in aircraft as air navigation aids. Others are ground-based, primarily to obtain a "fix" on a pilot requesting orientation assistance or to locate downed aircraft. A location "fix" is established by the intersection of two or more bearing lines plotted on a navigational chart using either two separately located Direction Finders to obtain a fix on an aircraft or by a pilot plotting the bearing indications of his Direction Finder (DF) on two separately located ground-based transmitters both of which can be identified on his chart. (FAA4) (FAA8)
Direction Finder (DF) Approach Procedure	Used under emergency conditions where another instrument approach procedure cannot be executed. Direction Finder (DF) guidance for an instrument approach is given by Air Traffic Control (ATC) facilities with DF capability. (FAA4)
Direction Finder (DF) Fix	The geographical location of an aircraft obtained by one or more direction finders. (FAA4)
Direction Finder (DF) Guidance	Headings provided to aircraft by facilities equipped with direction finding equipment. These headings, if followed, will lead the aircraft to a predetermined point such as the Direction Finder (DF) station or an airport. DF guidance is given to aircraft in distress or to other aircraft which request the service. Practice DF guidance is provided when workload permits. (FAA4)
Directional Route Miles	The mileage in each direction over which public transportation vehicles travel while in revenue service. It is computed with regard to direction but without regard to the number of traffic lanes or rail tracks existing in the ROW. (FTA1)
Disabling Damage	Damage which precludes departure of a motor vehicle from the scene of the accident in its usual manner in daylight after simple repairs. (49CFR390)
Disabling Injury	An injury causing death, permanent disability or any degree of temporary total disability beyond the day of the injury. (NSC1)
Disc Brake	A brake used primarily on rail passenger cars that uses brake shoes clamped by calipers against flat steel discs. (TRB1)
Discontinued Operations Income (Loss)	Gain or loss from disposal of investor controlled companies or nontransport ventures. Does not include earnings or losses from discontinued transport or transport-related operations. (BTS4)
Discrete Code	(See also Code; Decoder) As used in the Air Traffic Control Radar Beacon System (ATCRBS), any one of the 4096 selectable Mode 3/A aircraft transponder codes except those ending in zero ; e.g., discrete codes 0010, 1201, 2317, 7777; nondiscrete codes 0100, 1200, 7700. Nondiscrete codes are normally reserved for radar facilities that are not equipped with discrete decoding capability and for other purposes such as emergencies (7700), Visual Flight Rules (VFR) aircraft (1200), etc. (FAA4)
Discrete Frequency	A separate radio frequency for use in direct pilot-controller communications in air traffic control which reduces frequency congestion by controlling the number of aircraft operating on a particular frequency at one time. Discrete frequencies are normally designated for each control sector in en route/terminal Air Traffic Control (ATC) facilities. Discrete frequencies are listed in the Airport/Facility Directory and the Department of Defense (DOD) FLIP Instrument Flight Rules (IFR) En Route Supplement. (FAA4)
Dispatch Point	A location where arrangements may be made for the short term or trip rental use of an Interagency Fleet Management System (IFMS) vehicle. (GSA2)
Dispatch Vehicle	A vehicle provided to an individual or an organizational element of a government agency by GSA's Interagency Fleet Management System for short term use, usually on a day to day basis, not to exceed 30 consecutive days. (GSA1)
Displaced Threshold	A threshold located at a point on the runway other than at the beginning of the usable runway pavement. The displaced area is available for takeoff. (FAA12)
Displacement	The weight, in tons of 2,240 pounds, of the vessel and its contents. Calculated by dividing the volume of water displaced in cubic feet by 35, the average density of sea water. (MARAD2)
Disposable Income	Personal income less personal tax and non-tax payments. (DOE6)
Disposal Date	The date a vehicle is disposed of and no longer included in the inventory. (GSA2)
Disposal Storage	An inventory accountability category of vehicles not in use and scheduled for disposal. (GSA2)
Disposal Storage Date	The date a vehicle is taken out of service and placed in disposal storage. (GSA2)
Disqualification	1) The suspension, revocation, cancellation, or any other withdrawal by a State of a person's privileges to drive a commercial motor vehicle or 2) A determination by the Federal Highway Administration (FHWA), under the rules of practice for motor carrier safety contained in 49 CFR 386, that a person is no longer qualified to operate a commercial motor vehicle under 49 CFR 391; or 3) The loss of qualification which automatically follows conviction of an offense listed in 49 CFR 383.51. (49CFR383)
Distance Measuring Equipment (DME)	Airborne and ground equipment used to measure, in nautical miles, the slant range distance of an aircraft from the Distance Measuring Equipment (DME) navigational aid. (FAA4) (FAA6)
Distance Measuring Equipment (DME) Fix	A geographical position determined by reference to a navigational aid which provides distance and azimuth information. It is defined by a specific distance in nautical miles and a radial, azimuth, or course (i.e., localizer) in degrees magnetic from that aid. (FAA4)
Distance Measuring Equipment (DME) Separation	Spacing of aircraft in terms of distances (nautical miles) determined by reference to distance measuring equipment. (FAA4)
Distillate Fuel Oil	A general classification for one of the petroleum fractions produced in conventional distillation operations. Included are No. 1, No. 2, and No. 4 fuel oils and No. 1, No. 2, and No. 4 diesel fuels. Distillate fuel oil is used primarily for space heating, on- and off-highway diesel engine fuel (including railroad engine fuel and fuel for agricultural machinery), and electric power generation.
Distress	A condition of being threatened by serious and/or imminent danger and of requiring immediate assistance. (FAA4)
Distressed Unit	A person and/or property in peril to any degree. (USCG3)
Distributary	A branch of a river that flows away from the main stream and does not return to it. (TNDOT1)
Distribution Main	Generally, mains, services, and equipment that carry or control the supply of gas from the point of local supply to and including the sales meters. (AGA1)
Distributor	A company primarily engaged in the sale and delivery of natural and/or supplemental gas directly to consumers through a system of mains. (DOE5)
District Commander	The District Commander of the Coast Guard or his authorized representative, who has jurisdiction in the particular geographical area. (49CFR171)
Ditch Light	Spotlight aimed at right side of road. (ATA1)
Diverse Vector Area	In a radar environment, that area in which a prescribed departure route is not required as the only suitable route to avoid obstacles. The area in which random radar vectors below the Minimum Vectoring Altitude/Minimum Instrument Flight Rules Altitude (MVA/MIA), established in accordance with the Terminal Instrument Procedures criteria for diverse departures obstacles and terrain avoidance, may be issued to departing aircraft. (FAA4)
Divided Highway	A multi-lane facility with a curbed or positive barrier median, or a median that is 4 feet (1.2 meters) or wider. (FHWA2)
Division	An established point where driver ends trip. (ATA1)
Dock	(See also Marina, Pier, Wharf) For ships, a cargo handling area parallel to the shoreline; for land transportation, a loading or unloading platform at an industrial location or carrier terminal. (MARAD2)
Dock It	Park truck at dock. (ATA1)
Dock Receipt	A receipt used to transfer accountability when the export item is moved by the domestic carrier to the port of embarkation and left with the international carrier for export. (USTTA1)
Dock Walloper	One who loads and unloads vehicles and handles freight on the dock. (ATA1)
Dockage	(See also Wharfage) Charge assessed against a vessel for berthing at a wharf, pier, bulkhead structure, or bank or for mooring to a vessel so berthed. (MARAD1)
Documented Yacht	A vessel of five or more net tons owned by a citizen of the United States and used exclusively for pleasure with a valid marine document issued by the Coast Guard. Documented vessels are not numbered. (USCG2)
Documents Against Acceptance	Instructions given by a shipper to a bank indicating that documents transferring title to goods should be delivered to the buyer (or drawee) only upon the buyer's payment of the attached draft. (USTTA1)
Dog	Truck with little power. (ATA1)
Dog Chart	(See also Locking Dog) [with respect to rail operations] A diagrammatic representation of the mechanical locking of an interlocking machine, used as a working plan in making up, assembling and fitting the locking. (49CFR236)
Dog Tracks	Unit or straight truck that runs out of line. (ATA1)
Dolly	An auxiliary axle assembly having a fifth wheel used for purpose of converting a semitrailer to a full trailer. (ATA2)
Dolphin	(See also Mooring Cell) An isolated cluster of piles used as a support for mooring devices or marker lights. (TNDOT1)
Domestic	Produced in the United States, including the Outer Continental Shelf (OCS). (DOE5)
Domestic Air Defense Identification Zone	An Air Defense Identification Zone (ADIZ) within the United States along an international boundary of the United States. (FAA4)
Domestic Air Operator	Commercial air transportation within and between the 50 States and the District of Columbia. Includes operations of certificated route air carriers, Pan American, local service, helicopter, intra-Alaska, intra-Hawaii, all-cargo carriers and other carriers. Also included are transborder operations conducted on the domestic route segments of U.S. air carriers. Domestic operators are classified based on their operating revenue as follows Major (over $1 billion); National ($100-1,000 million); Large Regional ($10-99.9 million); Medium Regional ($0-9.99 million). (DOE6)
Domestic Airspace	Airspace which overlies the continental land mass of the United States plus Hawaii and U.S. possessions. Domestic airspace extends to 12 miles offshore. (FAA4)
Domestic Fleet	All reportable agency owned motor vehicles, operated in any State, Commonwealth, Territory or possession of the United States. (GSA1)
Domestic Freight	All waterborne commercial movements between points in the United States, Puerto Rico, and the Virgin Islands, excluding traffic with the Panama Canal Zone. Cargo moved for the military in commercial vessels is reported as ordinary commercial cargo; military cargo moved in military vessels is omitted. (TNDOT1)
Domestic Freight (Water)	All waterborne commercial movement between points in the United States, Puerto Rico, and the Virgin Islands, excluding traffic with the Panama Canal Zone. Cargo moved for the military in commercial vessels is reported as ordinary commercial cargo; military cargo moved in military vessels is omitted.
Domestic Intercity Trucking	Trucking operations within the territory of the United States, including intra-Hawaiian and intra-Alaskan, which carry freight beyond the local areas and commercial zones. (ATA2)
Domestic Operation	In general, operations within and between the 50 States of the United States, the District of Columbia, American Samoa, Caroline Islands. Guam Island, Johnston Island, Marianna Islands, Midway Island, Puerto Rico, U.S. Virgin Islands and Wake Island. (FAA15)
Domestic Operations	All air carrier operations having destinations within the 50 United States, the District of Columbia, Puerto Rico, and the U.S. Virgin Islands. (DOE5) (FAA14)
Domestic Operations (Air Carrier)	All air carrier operations having destinations within the 50 United States, the District of Columbia, the Commonwealth of Puerto Rico, and the U.S. Virgin Islands.
Domestic Passenger	Any person traveling on a public conveyance by water between points in the United States, Puerto Rico, and the Virgin Islands. (TNDOT1)
Domestic Passenger (Water)	Any person traveling on a public conveyance by water between points in the United States, Puerto Rico, and the Virgin Islands.
Domestic Transportation	Transportation between places within the United States other than through a foreign country. (49CFR171)
Donut Area	The area outside of the Federal Highway Administration (FHWA) approved adjusted boundary of one or more urbanized areas but within the boundary of a National Ambient Air Quality Standards (NAAQ) non-attainment area. (FHWA2)
Donut Areas	Geographic areas outside a metropolitan planning area boundary, but inside the boundary of a nonattainment or maintenance area that contains any part of a metropolitan area(s). These areas are not isolated rural nonattainment and maintenance areas.
Donuts	Truck tires. (ATA1)
Doodle Bug	Small tractor used to pull two axle dollies in a warehouse. (ATA1)
Door Sill Step	Any step normally protected from the elements by the cab door when closed. (49CFR399)
Double	(See also Rocky Mountain Double; Turnpike Double) A combination of two trailers pulled by a power unit. Usually refers to a power unit pulling two 28 foot trailers. (ATA2)
Double Bottom	Unit consisting of tractor, semitrailer and full trailer. Also called "twin trailers", "doubles." (ATA1)
Double Clutching	Shifting the gears of a truck transmission without clashing them. (ATA1)
Double Deck Bus	A bus with two separate passenger compartments, one above the other. (APTA1)
Double Decked Buses	High-capacity buses having two levels of seating, one over the other, connected by one or more stairways. Total bus height is usually 13 to 14.5 feet, and typical passenger seating capacity ranges from 40 to 80 people. (FTA1)
Double Heading Cock	A manually operated valve by means of which the control of brake operation is transferred to the leading locomotive. (49CFR236)
Double Lockage	See Double.
Double stack	Railcar movement of containers stacked two high.
Double Trip	The maneuver necessary when a towboat has more barges in tow than the power of the boat can handle in certain areas of swift current or conditions at the lock will permit. A tow will tie off below the swift water a portion of his tow, push the others above the questionable area, tie them off to the bank, and go back for the remainder of the tow. This is also a necessary maneuver in ice at times. (TNDOT1)
Down Draft	The natural tendency for the river current to pull objects downstream. (TNDOT1)
Down In the Corner	"Creeper" gear. (ATA1)
Down Shape of (Revetment, Shore, Etc.)	Running the shape of the shore, staying approximately the same distance off the shore at all times. (TNDOT1)
Downtime	The amount of time a vehicle or equipment is out of service for repair. (GSA2)
Downtown People Mover	A type of automated guideway transit vehicle operating on a loop or shuttle route within the central business district of a city. (APTA1)
Draft	1) Crosscurrent; tows will drift to the right or left depending on the draft (usually qualified as out draft, or left-or right-handed draft). 2) The depth of water a vessel draws, loaded or unloaded. (TNDOT1)
Drag Down	Shift too slowly to lower gears. (ATA1)
Drainage Basin	The land drained by a river system. (DOE5)
Draw Back	Repayment in whole or in part of duties or taxes paid on imported merchandise that is re-exported. (TNDOT1)
Draw Down	The procedure of spilling water through one dam prior to the arrival of excessive water from the upper reaches of the river. This maneuver is used when flash floods are expected or have occurred or where tributary streams are emptying excessive amounts of water into the main streams. (DOE5) (TNDOT1)
Draw Span	The movable portion of a bridge deck. (DOI3)
Drawbridge	A bridge that pivots or lifts so as to let a boat through. (TNDOT1)
Drayage	Transporting of rail or ocean freight by truck to an intermediate or final destination; typically a charge for pickup/delivery of goods moving short distances (e.g., from marine ter­minal to warehouse).
Dredge Material	Material that is excavated or dredged from waters of the United States. (TNDOT1)
Dredged Cut	1) One pass made by a dredge in a channel within the confines of the riverbed for the purpose of maintaining the proper depth of water; 2) a dredged channel. (TNDOT1)
Dredged Shipping Lane	Lane that has been dug out to provide an adequate depth of water for navigation. (DOI3)
Dredging	To clean, deepen or widen with a machine equipped with scooping or suction devices used in deepening harbors and waterways and in underwater mining. (BOC2)
Dredging Spoil	The discharge from a dredge. (TNDOT1)
Drift	1) The motion of a boat floating with no mechanical aid. 2) Debris floating in the river or lodged along shore in a drift pile. 3) Colloquially used as a synonym for currents "how does the drift set around this bridge pier?" Also referred to as "Current", "Set", or "Draft". (TNDOT1)
Drifting	Underway, but proceeding over the bottom without use of engines, oars or sails; being carried along only by the tide, current, or wind. (USCG2)
Drive	To use full power ahead. Also called Punch. (TNDOT1)
Drive Her Through	To proceed full speed ahead. (TNDOT1)
Driveaway-Towaway	Refers to a carrier operation, such as a fleet of tow trucks, used to transport other vehicles, when some or all wheels of the vehicles being transported touch the road surface. (FHWA4)
Driveaway-Towaway Operation	Any operation in which a motor vehicle constitutes the commodity being transported and one or more set of wheels of the vehicle being transported are on the surface of the roadway during transportation. (49CFR390)
Driver	1) A person who operates a motorized vehicle. If more than one person drives on a single trip, the person who drives the most miles is classified as the principal driver. 2) An occupant of a vehicle who is in physical control of a motor vehicle in transport or, for an out of-control vehicle, an occupant who was in control until control was lost. (FHWA3) (NHTSA3)
Driver Applicant	An individual who applies to a State to obtain, transfer, upgrade, or renew a commercial driver's license (CDL). (49CFR383)
Drivers	Drive wheels. (ATA1)
Driver's License	A license issued by a State or other jurisdiction, to an individual which authorizes the individual to operate a motor vehicle on the highways. (49CFR383)
Driving a Commercial Motor Vehicle While Under the Influence of Alcohol	Committing any one or more of the following acts in a commercial motor vehicle (CMV) driving a CMV while the person's alcohol concentration is 0.04 percent or more; driving under the influence of alcohol, as prescribed by State law; or refusal to undergo such testing as is required by any State or jurisdiction in the enforcement of 49 CFR 383.51b)2)(i)a) or b), or 49 CFR 392.5a)2). (49CFR383) (49CFR390)
Driving Piece	A crank secured to a locking shaft by means of which horizontal movement is imparted to a longitudinal locking bar. (49CFR236)
Driving Under the Influence (DUI)	The driving or operating of any vehicle or common carrier while drunk or under the influence of liquor or narcotics. (FTA1)
Drop It On the Nose	Uncoupling a tractor from a semitrailer without lowering the landing gear to support the trailer's front end. (ATA1)
Drop the Body	Unhook and drive a tractor away from a parked semi. (ATA1)
Dropping Out Line	A line used in dropping a barge out of a tow. (TNDOT1)
Drum	A flat-ended or convex-ended cylindrical packaging made of metal, fiberboard, plastic, plywood, or other suitable materials. This definition also includes packagings of other shapes made of metal or plastic (e.g., round taper-necked packagings or pail-shaped packagings) but does not include cylinders, jerricans, wooden barrels or bulk packagings. (49CFR171)
Dry Bulk Cargo	Cargo which may be loose, granular, free-flowing or solid, such as grain, coal, and ore, and is shipped in bulk rather than in package form. Dry bulk cargo is usually handled by specialized mechanical handling equipment at specially designed dry bulk terminals. (MARAD1)
Dry Cargo	Cargo that does not require temperature control. (MARAD2)
Dry Cargo Barges (Water)	Large flat-bottomed, nonself-propelled vessels used to transport dry-bulk materials such as coal and ore.
Dry Gas	Natural gas from which the entrained liquids and nonhydrocarbon gases have been removed by lease facilities and/or plant processing. This is the gas that the interstate pipeline purchased, or expects to purchase, to serve its annual requirements. (DOE5)
Dry Hole	An exploratory or development well found to be incapable of producing either oil or gas in sufficient quantities to justify completion as an oil or gas well. (DOE5)
Dry-Bulk Container	A container constructed to carry grain, powder and other free-flowing solids in bulk. Used in conjunction with a tilt chassis or platform. (MARAD2)
Drydock	An artificial basin fitted with gate or caisson into which a vessel may be floated and from which the water may be pumped out to expose the bottom of the vessel. (DOI4)
Drydock Gate	Gate at the entrance to a drydock. (DOI3)
Dual Drive	(See also Tandem) Box axles have drive mechanisms and are connected to engine power output. 1) pusher tandem only the rearmost axle is driving type and the forward unit is free rolling, also called "dead axle"; 2) tag axle forward unit of tandem is driving type while rear unit is free rolling. (TII1) (TII2)
Duals	A pair of tires mounted together. (ATA1)
Duck Water	Slack water. Smooth water generally found on the inside shore of a river bend, under a point, under a bar, etc. (TNDOT1)
Dumb Barge	Slang term for a barge that does not have its own power. (TNDOT1)
Dump Body	Truck body of any type which can be tilted to discharge its load. (ATA1)
Dusting	Driving with wheels on road shoulder, thereby causing a cloud of dust. (ATA1)
Duty	A tax imposed by a government on imports. (TNDOT1)
Dynamic Routing	In demand-response transportation systems, the process of constantly modifying vehicle routes to accommodate service requests received after the vehicle began operations, as distinguished from predetermined routes assigned to a vehicle. (TRB1)
Dynamite the Brakes	Emergency stop using every brake on the unit. (ATA1)
Earth Surface	The outermost surface of the land and waters of the planet. (DOI4)
Economies of Scale	Cost reductions or productivity efficiencies achieved through size-optimization in relation to operational circumstances. For example, commodity freight rates usually decline as the volume of cargo tonnage shipped increases. (MARAD1)
Economy	Transport service established for the carriage of passengers at fares and quality of service below that of coach service. (BTS5)
Eddy	A current running contrary to the main current, causing water turbulence, e.g., below the bridge pier where a swift current is passing through, or below a bar or point. (TNDOT1)
Eddy Above and Below	Channel report term meaning that eddies should be expected both above and below the object mentioned in the marks, such as dikes, top and bottom of crossings, sunken obstructions, etc.; tricky water. (TNDOT1)
Eddy Extends Way Out	Term meaning that an eddy extends from the shore or the dike into or across the range formed by this set of marks, or extends one-third or more across the river. (TNDOT1)
Eddy Makes Out from Right (Left) Shore	Term indicating that one should watch for eddy along the shore designated in this set of marks. (TNDOT1)
Effective Intensity	That intensity of a light in candela as defined by the Illuminating Engineering Society's Guide for Calculating the Effective Intensity of Flashing Signal Lights, November, 1964. (49CFR221)
Effective Locking Device	A manually operated switch or derail which is 1) Vandal resistant; 2) Tamper resistant; and 3) Capable of being locked and unlocked only by the class, craft or group of employees for whom the protection is being provided. (49CFR218)
Ejection	Refers to occupants being totally or partially thrown from the vehicle as a result of an impact or rollover. (NHTSA2) (NHTSA3)
Electric Lock	[with respect to rail operations] A device to prevent or restrict the movement of a lever, a switch or a movable bridge, unless the locking member is withdrawn by an electrical device such as an electromagnet, solenoid or motor. (49CFR236)
Electric Locking	[with respect to rail operations] The combination of one or more electric locks and controlling circuits by means of which levers of an interlocking machine, or switches or other units operated in connection with signaling and interlocking, are secured against operation under certain conditions. (49CFR236)
Electric System	Physically connected generation, transmission, and distribution facilities operated as an integrated unit under one central management or operating supervision. (DOE5)
Electricity	(See also Gigawatt, Kilowatt, Megawatt) A form of energy generated by friction, induction, or chemical change that is caused by the presence and motion of elementary charged particles of which matter consists. (DOE5)
Electro-Pneumatic Switch	A switch operated by an electro-pneumatic switch-and-lock movement. (49CFR236)
Electro-Pneumatic Valve	A valve electrically operated which, when operated, will permit or prevent passage of air. (49CFR236)
Elevated on Fill	Rail transit way above surface level fill. Transition segments above surface level on fill are included. (FTA1)
Elevated on Structure	Rail transit way above surface level on structure. Transition segments above surface level on structures are included. (FTA1)
Elevated Rail Subway	Includes elevated and subway trains in a city. (FHWA3)
Elevated Temperature Material	A material which, when offered for transportation or transported in a bulk packaging 1) Is in a liquid phase and at a temperature at or above 100 degrees C (212 degrees F); 2) Is in a liquid phase with a flash point at or above 37.8 degrees C (100 degrees F) that is intentionally heated and offered for transportation or transported at or above its flash point; or 3) Is in a solid phase and at a temperature at or above 240 degrees C (464 degrees F). (49CFR171)
Elevator	Hydraulic end-gate. (ATA1)
Embankment	A raised structure of earth, ground, etc. (DOI4)
Emergency	A deviation from normal operation, a structural failure, or severe environmental conditions that probably would cause harm to people or property. (49CFR193)
Emergency Brake	A mechanism designed to stop a motor vehicle after a failure of the service brake system. (49CFR571)
Emergency Brake System	A mechanism designed to stop a vehicle after a single failure occurs in the service brake system of a part designed to contain compressed air or brake fluid or vacuum (except failure of a common valve, manifold brake fluid housing or brake chamber housing). (49CFR393)
Emergency Contingency Vehicles	Revenue vehicles placed in an inactive contingency fleet for energy or other local emergencies after the revenue vehicles have reached the end of their normal minimum useful life. The vehicles must be properly stored and maintained, and the Emergency Contingency Plan must be approved by FTA. Substantial changes to the plan (10% change in fleet) require re-approval by FTA. (FTA1)
Emergency Locator Transmitter (ELT) (ELT)	A radio transmitter attached to the aircraft structure which operates from its own power source on 121.5 MHz and 243.0 MHz. It aids in locating downed aircraft by radiating a downward sweeping audio tone, 2-4 times per second. It is designed to function without human action after an accident. (FAA4) (FAA8)
Emergency Opening Window	That segment of a side facing glazing location which has been designed to permit rapid and easy removal during a crisis situation. (49CFR223)
Emergency Preparedness Plan	A comprehensive plan which identifies potential emergencies and their impact on the community, and identifies operating procedures and actions to put in place during actual emergencies.
Emergency Relief	An operation in which a motor carrier or driver of a commercial motor vehicle is providing direct assistance to supplement State and local efforts and capabilities to save lives or property or to protect public health and safety as a result of an emergency. (49CFR390)
Emission Standards	Standards for the levels of pollutants emitted from automobiles and trucks. Congress established the first standards in the Clean Air Act of 1963. Currently, standards are set for four vehicle classes - automobiles, light trucks, heavy duty gasoline trucks, and heavy-duty diesel trucks. (DOE6)
Emissions Budget	The part of the State Implementation Plan (SIP) that identifies the allowable emissions levels, mandated by the National Ambient Air Quality Standards (NAAQS), for certain pollutants emitted from mobile, stationary, and area sources. The emissions levels are used for meeting emission reduction milestones, attainment, or maintenance demonstrations.
Emissions Inventory	A complete list of sources and amounts of pollutant emissions within a specific area and time interval.
Employee	1) A driver of a commercial motor vehicle (including an independent contractor while in the course of operating a commercial motor vehicle); 2) A mechanic; 3) A freight handler; 4) Any individual, other than an employee, who is employed by an employer and who in the course of his or her employment directly affects commercial motor vehicle safety, but such term does not include an employee of the United States, any State, any political subdivision of a State, or any agency established under a compact between States and approved by the Congress of the United States who is acting within the course of such employment. (49CFR390)
Employee Hours	The number of hours worked by all employees of the railroad during the previous calendar year. (49CFR245)
Employee Human Factor	(See also Human Factor) Includes any of the accident causes signified by the rail equipment accident/incident cause codes listed under "Train Operation-Human Factors" in the current "Federal Railroad Administration (FRA) Guide for Preparing Accident/Incident Reports," except for Cause Code 506. (49CFR225)
Employee Not On Duty	A railroad employee who is on railroad property for a purpose connected with his or her employment or with other railroad permission, but who is not engaged in rail operations for financial or other compensation. (FRA3)
Employee On Duty (Class A)	Those persons who are engaged in the operation of a railroad. Ordinarily the fact that the employee is or is not under pay will determine whether he or she is "on duty". However, employees on railroad property while on rest or meal periods, "training time", or doing work which they are expected to do, but actually perform before pay starts, must be considered as "employees on duty." (FRA2)
Employee On Duty (Class B)	Those employees who are on railroad property for purposes connected with their employment or with other railroad permission, but who are not "on-duty" as defined above. (FRA2)
Employer	Any person engaged in a business affecting interstate commerce who owns or leases a commercial motor vehicle in connection with that business, or assigns employees to operate it, but such terms does not include the United States, any State, any political subdivision of a State, or an agency established under a compact between States approved by the Congress of the United States. (49CFR390)
Empty Car Mile	An empty car mile is a mile run by a freight car without a load. In the case of intermodal movements, the car miles generated will be loaded or empty depending on whether the trailers/containers are moved with or without a waybill, respectively. (AAR1)
En Route	One of three phases of flight services (terminal, en route, oceanic). En route service is provided outside of terminal airspace and is exclusive of oceanic control. (FAA8)
En Route Air Traffic Control Service	Air traffic control service provided for aircraft on Instrument Flight Rules (IFR) flight plans, generally by Air Route Traffic Control Center (ARTCC), when these aircraft are operating between departure and destination terminal areas. When equipment capabilities and controller workload permit, certain advisory/assistance services may be provided to Visual Flight Rules (VFR) aircraft. (FAA4) (FAA8)
En Route Center	An Air Route Traffic Control Center. (FAA3)
En Route Descent	Descent from the en route cruising altitude which takes place along the route of flight. (FAA4)
En Route Facility Activity	Total Instrument Flight Rules aircraft handled ; (2 x departures) + Domestic and Oceanic Overflights. (FAA3)
En Route High Altitude Charts	Provide aeronautical information for en route instrument navigation (IFR) in the high altitude stratum. Information includes the portrayal of jet routes, identification and frequencies of radio aids, selected airports, distances, time zones, special uses airspaces, and related information. (FAA4)
En Route Low Altitude Charts	Provide aeronautical information for en route instrument navigation (IFR) in the low altitude stratum. Information includes the portrayal of airways, limits of controlled airspace, position identification and frequencies of radio aids, selected airports, minimum en route and minimum obstruction clearance altitudes, airway distances, reporting points, restricted areas, and related data. Area charts, which are a part of this series, furnish terminal data at a larger scale in congested areas. (FAA4)
En Route Minimum Safe Altitude Warning	A function of the National Airspace System (NAS) Stage A en route computer that aids the controller by alerting him when a tracked aircraft is below or predicted by the computer to go below a predetermined minimum Instrument Flight Rules (IFR) altitude (MIA). (FAA4) (FAA8)
En Route Spacing Program	A program designed to assist the exit sector in achieving the required in trail spacing. (FAA4)
End Facing Glazing Location	Any location where a line perpendicular to the plane of the glazing material makes a horizontal angle of 50 degrees or less with the centerline of the locomotive, caboose or passenger car. Any location which, due to curvature of the glazing material, can meet the criteria for either a front facing location or a side facing location shall be considered a front facing location. (49CFR223)
Ending Milepost	The continuous milepost notation, to the nearest 0.01 mile that marks the end of any road or trail segment. (DOI2)
Endorsement	An amendment to an insurance policy. (49CFR387)
End-Use Energy Consumption	Primary end-use energy consumption is the sum of fossil fuel consumption by the four end-use sectors (residential, commercial, industrial, and transportation) and generation of hydroelectric power by nonelectric utilities. Net end-use energy consumption includes electric utility sales to those sectors but excludes electrical system energy losses. Total end-use energy consumption includes both electric utility sales to the four end-use sectors and electrical system energy losses. (DOE3)
End-Use Sectors	The residential, commercial, industrial, and transportation sectors of the economy. (DOE3)
Energy	The capacity for doing work as measured by the capability of doing work (potential energy) or the conversion of this capability to motion (kinetic energy). Energy has several forms, some of which are easily convertible and can be changed to another form useful for work. Most of the world's convertible energy comes from fossil fuels that are burned to produce heat that is then used as a transfer medium to mechanical or other means in order to accomplish tasks. Electrical energy is usually measured in kilowatt hours, while heat energy is usually measured in British thermal units. (DOE3) (DOE5)
Energy Capacity	Measured in kilowatt hours. The energy delivered by the battery, when tested at C/3 discharge rate, up to termination of discharge specified by the battery manufacturer. The required acceleration power must be delivered by the battery at any point up to 80% of the battery's energy capacity rating. (DOE6)
Energy Consumption	The use of energy as a source of heat or power or as an input in the manufacturing process. (DOE3)
Energy Efficiency	The ratio of energy inputs to outputs from a process, for example, miles traveled per gallon of fuel (mpg).
Energy Efficient Motors	Are also known as "high-efficiency motors" and "premium motors." They are virtually interchangeable with standard motors, but differences in construction make them more energy efficient. (DOE5)
Energy Information Administration (EIA)	An independent agency within the U.S. Department of Energy that develops surveys, collects energy data, and analyzes and models energy issues. The Agency must meet the requests of Congress, other elements within the Department of Energy, Federal Energy Regulatory Commission, the Executive Branch, its own independent needs, and assist the general public, or other interest groups, without taking a policy position. (DOE5)
Energy Intensity	In reference to transportation, the ratio of energy inputs to a process to the useful outputs form that process; for example, gallons of fuel per passenger-mile or Btu per ton-mile. (DOE6)
Energy Source	A substance, such as petroleum, natural gas, or coal, that supplies heat or power. In Energy Information Administration reports, electricity and renewable forms of energy, such as biomass, geothermal, wind, and solar, are considered to be energy sources. (DOE3) (DOE5)
Engine	A locomotive propelled by any form of energy and used by a railroad. (49CFR171)
Engine Classification	A 2-digit numeric code identifying vehicle engines by the number of cylinders. (GSA2)
Engine Displacement	(See also Cylinder, Engine Size) The volume in inches, through which the head of the piston moves, multiplied by the number of cylinders in the engine. Also known as cubic inch displacement (CID), may also be measured in liters. (GSA2)
Engine Retarder	Electronic equipment which governs engine speed control. (BOC3)
Engine Size	(See also Cylinder, Engine Displacement) The total volume within all cylinders of an engine, when pistons are at their lowest positions. The engine is usually measured in "liters" or "cubic inches of displacement (CID)." Generally, larger engines result in greater engine power, but less fuel efficiency. There are 61.024 cubic inches in a liter. (DOE4) (DOE5)
Engineer	A person responsible for operating and maintaining the power system on a vessel. (TNDOT1)
English Units	The term "English" refers to the United States legislative interpretation of the units as defined in a document prepared by the National Institute of Standards and Technology (NIST), U.S. Department of Commerce, Special Publication 330. Commonly used English units in Highway Performance Monitoring System (HPMS) are miles, feet, and inches. (FHWA2)
Enhancement Activities	Refers to activities related to a particular transportation project that 'enhance' or contribute to the existing or proposed project. Examples of such activities include provision of facilities for pedestrians or cyclists, landscaping or other scenic beautification projects, historic preservation, control and removal of outdoor advertising, archaeological planning and research, and mitigation of water pollution due to highway runoff.
Enplaned Passenger	The total number of revenue passengers boarding aircraft. (FAA15)
Enplaned Passengers (Air Carrier)	See Revenue Passenger Enplanements.
Enplaned Revenue Tons of Freight and Mail	The number of revenue tons of freight and mail loaded on an aircraft including originating and transfer tons. (FAA15)
Enplanement	Domestic, territorial, and international revenue passengers who board an aircraft in the states in scheduled and non-scheduled service of aircraft in intrastate, interstate, and foreign commerce and includes intransit passengers (passengers on board international flights that transit an airport in the US for non-traffic purposes). (FAA11)
Entitlement	See Apportionment.
Entrapment	Refers to persons being partially or completely in the vehicle and mechanically restrained by a damaged vehicle component. Jammed doors and immobilizing injuries, by themselves, do not constitute entrapment. Occupants pinned by cargo shift are not considered to be entrapped. Occupants who are completely or partially ejected and subsequently become pinned by their own vehicle and any surface other than their own vehicle are not considered entrapped. An occupant whose seat belt buckle release mechanism is jammed as a result of a crash is not considered entrapped. (NHTSA2)
Entry Point	The point at which an aircraft transitions from an offshore control area to oceanic airspace. (FAA4)
Environmental Impact Statement (EIS)	Report developed as part of the National Environmental Policy Act requirements, which details any adverse economic, social, and environmental effects of a proposed transportation project for which Federal funding is being sought. Adverse effects could include air, water, or noise pollution; destruction or disruption of natural resources; adverse employment effects; injurious displacement of people or businesses; or disruption of desirable community or regional growth.
Environmental Justice (EJ)	Environmental justice assures that services and benefits allow for meaningful participation and are fairly distributed to avoid discrimination.
Environmental Protection Agency (EPA)	The federal regulatory agency responsible for administering and enforcing federal environmental laws, including the Clean Air Act, the Clean Water Act, the Endangered Species Act, and others.
Environmental Protection Agency Certification Files	Computer files produced by Environmental Protection Agency (EPA) for analysis purposes. For each vehicle make, model and year, the files contain the EPA test Miles Per Gallon (MPG) (city, highway and 55/45 composite). These MPG's are associated with various combinations of engine and drive-train technologies (e.g., number of cylinders, engine size, gasoline or diesel fuel, and automatic or manual transmission). These files also contain information similar to that in the Department of Energy (DOE)/EPA Gas Mileage Guide, although the MPG's in that publication are adjusted for shortfall. (DOE4) (DOE5)
Environmental Protection Agency Composite Mile Per Gallon (MPG)	The harmonic mean of the Environmental Protection Agency (EPA) city and highway MPG, weighted under the assumption of 55 percent city driving and 45 percent highway driving. (DOE4) (DOE5)
Environmental Restoration	Re-establishment (including all site preparation activities) of natural habitats or other environmental resources on a site where they formerly existed or currently exist in a substantially degraded state. This can include the restitution for the loss, damage, or destruction of natural resources arising out of the accidental discharge, dispersal, release or escape into or upon the land, atmosphere, watercourse, or body of water of any commodity transported by a motor carrier. This also may include the on-site or offsite replacement of wetlands and other natural habitats lost through development activities. (49CFR387 and 23CFR 777)
Environmentally Sensitive Area	An area of environmental importance having natural resources which if degraded may lead to significant adverse, social, economic or ecological consequences. These could be areas in or adjacent to aquatic ecosystems, drinking water sources, unique or declining species habitat, and other similar sites. (49CFR194)
Equalizing Reservoir	An air reservoir connected with and adding volume to the top portion of the equalizing piston chamber of the automatic brake valve, to provide uniform service reductions in brake pipe pressure regardless of the length of the train. (49CFR236)
Equipment Code	A six digit numeric code used to classify equipment by its usage characteristics (passenger carrying, cargo hauling, etc.), gross weight rating, and equipment configuration (panel truck, pick-up, stake body, dump etc.). (GSA2)
Equipment Consist	An equipment consist is a train, locomotive(s), cut of cars, or a single car not coupled to another car or locomotive. (FRA2) (FRA4)
Equipment Damage	All costs, including labor and material, associated with the repair or replacement-in-kind of on-track rail equipment. Trailers/container on flat cars are considered to be lading and damage to these is not to be included in on-track equipment damage. Damage to a flat car carrying a trailer/container is to be included in reportable damage. (FRA2)
Equivalent Airspeed	The calibrated airspeed of an aircraft corrected for adiabatic compressible flow for the particular altitude. Equivalent airspeed is equal to calibrated airspeed in standard atmosphere at sea level. (14CFR1)
Establishment	A single physical location where business is conducted or where services or industrial operations are performed. Examples of railroad establishments include, but are not limited to an operating division; general office; and a major installation such as a locomotive or car repair or construction facility. For employees who are engaged in dispersed operations, such as track maintenance workers, the "establishment' is the location where these employees report for work assignments. (FRA2)
Estimate Ratio	(See also Mean; Ratio Estimate) The ratio of two population aggregates (totals). For example, "average miles traveled per vehicle" is the ratio of total miles driven by all vehicles, over the total number of vehicles, within any subgroup. There are two types of ratio estimates; those computed using aggregates for vehicles and those computed using aggregates for households. (DOE5)
Estimated Arrival Time	The time the flight is estimated to arrive at the gate (scheduled operators) or the actual runway on times for nonscheduled operators. (FAA4)
Estimated Elapsed Time	The estimated time required to proceed from one significant point to another. (FAA4)
Estimated En Route Time	The estimated flying time from departure point to destination (lift-off to touchdown). (FAA4)
Estuary	The lower end of a river, or a semi-enclosed coastal body of water with access to the open ocean, which is affected by the tides and where fresh and salt water mix. (DOI3)
Ethanol	A clear, colorless, flammable oxygenated hydrocarbon with a boiling point of 78.5 °C in the anhydrous state. It is used in the United States as a gasoline octane enhancer and oxygenate (10 percent concentration). Ethanol can be used in high concentrations in vehicles optimized for its use. Otherwise known as ethyl alcohol, alcohol, or grain-spirit.
Evaluation of alternatives	A synthesis of the information generated by an analysis in which judgments are made on the relative merits of alternative actions.
Event	See also Accident, Casualty, Collision, Crash, Derailment, Fatality, Incident, Injury.
Event Recorder	A device, designed to resist tampering, that monitors and records data on train speed, direction of motion, time, distance, throttle position, brake applications and operations (including train brake, independent brake, and, if so equipped, dynamic brake applications and operations) and, where the locomotive is so equipped, cab signal aspect(s), over the most recent 48 hours of operation of the electrical system of the locomotive on which it is installed. (49CFR229)
Ex Quay	The seller makes the goods available to the buyer on the quay (wharf) at the destination named in the sales contract. The seller has to bear the full cost and risk involved in bringing the goods there. (USTTA1)
Ex Ship	The seller will make the goods available to the buyer on board the ship at the destination named in the sales contract. The seller bears all costs and risks involved in bringing the goods to the destination. (USTTA1)
Ex Ship's Tackle (EST)	Similar to Cost, Insurance and Freight, but seller is responsible for loss and damage until goods are delivered on dock at port of destination. Seller has to insure goods up to this point. Also called "ex ship." (TNDOT1)
Ex Warehouse	Buyer is responsible for all charges to destination and has to arrange insurance to cover the goods from the time they leave the warehouse at the place of shipment until their arrival at final destination. Also called "ex works." (TNDOT1)
Ex Works	See Ex Warehouse.
Excess	Any property under the control of a Federal Agency which that agency determines is not required for its needs or for the discharge of its responsibilities. (GSA2)
Excess Baggage Revenue	Revenues from the transportation by air of passenger baggage in excess of the free allowance. (BTS4)
Exclusion Zone	An area surrounding a Liquified Natural Gas (LNG) facility in which an operator or government agency legally controls all activities in accordance with 49 CFR 193.2057 and 49 CFR 193.2059 for as long as the facility is in operation. (49CFR193)
Exclusive Right-Of-Way	(See also Controlled Access Rights-of-Way) A highway or other facility that can only be used by buses or other transit vehicles. (APTA1)
Exclusive Rights-Of-Way	Roadways or other right-of-way reserved at all times for transit use and/or other high occupancy vehicles. The restriction must be sufficiently enforced so that 95 percent of vehicles using the right-of-way are authorized to use it. (FTA1)
Executive Transportation	Any use of an aircraft by a corporation, company, or other organization for the purposes of transporting its employees and/or property not for compensation or hire, and employing professional pilots for the operation of the aircraft. (FAA2) (FAA10) (FAA14)
Exempt Carrier	A for hire interstate operator [which] transports commodities or provides types of services that are exempt from federal regulation, could also operate within exempt commercial zones. (BOC4)
Exempt Intracity Zone	The geographic area of a municipality or the commercial zone of that municipality described by the Interstate Commerce Commission (ICC) in 49 CFR 1048, revised as of October 1, 1975. The descriptions are printed in appendix F to subchapter B of 49 CFR, Chapter III, Subchapter B. The term "exempt intracity zone" does not include any municipality or commercial zone in the State of Hawaii. For the purposes of 49 CFR 390.3(g), a driver may be considered to operate a vehicle wholly within an exempt intracity zone notwithstanding any common control, management, or arrangement for a continuous carriage or shipment to or from a point without such zone. (49CFR390)
Exempt Motor Carrier	A person engaged in transportation exempt from economic regulation by the Interstate Commerce Commission (ICC) under 49 U.S.C. 10526. "Exempt motor carriers" are subject to the safety regulations set forth in 49 CFR, Chapter III, Subchapter B. (49CFR390)
Exemption	A temporary or permanent grant, license or form of legal permission given by an agency to deviate from a regulation or provision of law administered by that agency. Issued in response to a petition for relief submitted by an individual or company. (USCG1)
Expandable	Flatbed trailer which can be expanded beyond its regular length to carry larger shipments. (ATA1)
Expect Altitude At Time or Fix	Used under certain conditions to provide a pilot with an altitude to be used in the event of two-way communications failure. It also provides altitude information to assist the pilot in planning. (FAA4)
Expect Further Clearance	Used to inform a pilot of the routing he can expect if any part of the route beyond a short range clearance limit differs from that filed. (FAA4)
Expected Departure Clearance Time (EDCT) (EDCT)	The runway release time assigned to an aircraft in a controlled departure time program and shown on the flight progress strip as an EDCT. (FAA4)
Expedite	Used by Air Traffic Control (ATC) when prompt compliance is required to avoid the development of an imminent situation. (FAA4)
Expenditure	All amounts of money paid out by a government, net of recoveries and other correcting transactions, other than retirement of debt, investment in securities, extension of credit, or agency transactions. Federal expenditures are also referred to as outlays. (BTS3)
Expenditures	1) Actual cash (or electronic transfer) payments made to the States or other entities. Outlays are provided as reimbursement for the Federal share for approved highway program activities. 2) A term signifying disbursement of funds for repayment of obligations incurred. An electronic transfer of funds, or a check sent to a State highway or transportation agency for voucher payment, is an expenditure or outlay.
Experimental Aircraft	An aircraft which does not have a type design or does not meet other certification standards. The "experimental" designation is one of several "Special Airworthiness Certificates" which allows the aircraft to operate in U.S. airspace. None may be used for commercial purposes. Experimental aircraft are divided into three groups 1) amateur built an aircraft, built by one or more persons who undertake the effort for the purpose of recreation and education; 2) exhibition a unique (one-of-a-kind) aircraft, a replica, a foreign or U.S. military surplus aircraft which may be used for exhibition purposes-movie and television productions, or sanctioned, organized events where the unique or unusual characteristics of the aircraft can be displayed; 3) other includes experimental aircraft that are not amateur or exhibition. This includes aircraft involved in research and development, crew training, market surveys, air racing, those used to show compliance with regulations and the like. (FAA6)
Explosion-Detonation	An accident/incident caused by the detonation of material carried by or transported by rail. A detonation occurs when a shock wave exceeds the speed of sound. Explosions-detonations resulting from mishaps during loading or unloading operations, and those caused by fire aboard on-track equipment are included in this definition. (FRA2)
Export License	A government document permitting designated goods to be shipped out of the country as specified. (TNDOT1)
Exports	1) Outbound international freight, including re-export of foreign merchandise. 2) Shipments of goods from the 50 States and the District of Columbia to foreign countries and to Puerto Rico, the Virgin Islands, and other U.S. possessions and territories. (DOE3) (DOE5) (TNDOT1)
Exposed Pipeline	A pipeline where the top of the pipe is protruding above the seabed in water less than 15 feet deep, as measured from the mean low water. (49CFR195)
Express Body	Open box truck body. (ATA1)
Express Bus	A bus that operates a portion of the route without stops or with a limited number of stops. (APTA1)
Expressway	A controlled access, divided arterial highway for through traffic, the intersections of which are usually separated from other roadways by differing grades.
Extended Over-Water Operations	1) With respect to aircraft other than helicopters, an operation over water at a horizontal distance of more than 50 nautical miles from the nearest shoreline; and 2) With respect to helicopters, an operation over water at a horizontal distance of more than 50 nautical miles from the nearest shoreline and more than 50 nautical miles from an off-shore heliport structure. (14CFR1)
External Combustion Engine	An engine in which fuel combustion takes place outside the cylinder, turbine, or the like and in which energy is turned into mechanical force; for example, a steam engine. (TRB1)
External Load	A load that is carried, or extends, outside of the aircraft fuselage. (14CFR1)
External Load Attaching	The structural components used to attach an external load to an aircraft, including external-load containers, the backup structure at the attachment points, and any quick-release device used to jettison the external load. (14CFR1)
Extraordinary Items Income (Loss)	Income or loss which can be characterized as material, unusual and of infrequent occurrence. (BTS4)
Face Line	A line used from head of boat to the tow. (TNDOT1)
Face Up	To make-up the towboat to the tow (i.e., maneuver barges into position and secure for towing). (TNDOT1)
Face Wires	Heavy cables securing boat to tow (i.e., pusher to barge). (TNDOT1)
Facility	All or any portion of buildings, structures, sites, complexes, equipment, roads, walks, passageways, parking lots, or other real or personal property, including the site where the building, property, structure, or equipment is located. (49CFR37)
Facing Movement	The movement of a train over the points of a switch which face in a direction opposite to that in which the train is moving. (49CFR236)
Facing Point Lock Plunger	[with respect to rail operations] That part of a facing point lock which secures the lock rod to the plunger stand when the switch is locked. (49CFR236)
Facing Point Switch	[with respect to rail operations] A switch, the points of which face traffic approaching in the direction for which the track is signaled. (49CFR236)
Factory Investigative Audit	The presence of the Officer in Charge of Marine Inspection (OCMI) and other Coast Guard personnel at a manufacturing facility to gather information and evidence to prove or disprove violations of the statutes, or to investigate potential defects which may present substantial risks of personal injury. (USCG1)
Fahrenheit	A temperature scale on which the boiling point of water is at 212 degrees above zero on the scale and the freezing point is at 32 degrees above zero at standard atmospheric pressure. (DOE5)
Fair Market Value	The value of a vehicle as stated by the National Automotive Dealers Association (NADA) or other sale publication. For vehicles under the 3-year replacement cycle, Fair Market Value is the average loan indicated in the appropriate NADA publication. (GSA2)
Fairly Close	As close to the shore, dike, or light as practicable (approximately 150 feet off). (TNDOT1)
Fallen Skier	A person who has fallen off their water skies. (USCG2).
Falling River	The river condition when gage readings are decreasing day by day. (TNDOT1)
Fare	The required payment for a ride on a public transportation vehicle. It may be paid by any acceptable means, for example, cash, token, ticket, transfer, farecard, voucher, or pass or user fee. (TRB1)
Fare Evasion	The unlawful use of transit facilities by riding without paying the applicable fare. (FTA1)
Fare Recovery Ratio	The ratio of fare revenue to operating expenses. (TRB1)
Farm Vehicle Driver	A person who drives only a motor vehicle that is 1) Controlled and operated by a farmer as a private motor carrier of property; 2) Being used to transport either agricultural products, or farm machinery, farm supplies, or both, to or from a farm; 3) Not being used in the operation of a for-hire motor carrier; 4) Not carrying hazardous materials of a type or quantity that requires the vehicle to be placarded in accordance with 49 CFR 177.823 and 5) Being used within 150 air-miles of the farmer's farm. (49CFR390)
Farm-To-Market Agricultural Transportation	The operation of a motor vehicle controlled and operated by a farmer who 1) Is a private motor carrier of property; 2) Is using the vehicle to transport agricultural products from a farm owned by the farmer, or to transport farm machinery or farm supplies to or from a farm owned by the farmer; and 3) Is not using the vehicle to transport hazardous materials of a type or quantity that require the vehicle to be placarded in accordance with 49 CFR 177.823. (49CFR390)
Fast File	A system whereby a pilot files a flight plan via telephone that is tape recorded and then transcribed for transmission to the appropriate air traffic facility. Locations having a fast file capability are contained in the Airport/Facility Directory. (FAA4)
Fatal Accident	(See also Fatality) Statistics reported to the Federal Highway Administration (FHWA) shall conform to the 30-day rule, i.e., a fatality resulting from a highway vehicular accident is to be counted only if death occurs within 30 days of the accident. (FHWA2)
Fatal Accident Rate	The fatal accident rate is the number of fatal accidents per 100 million vehicle miles of travel. (FHWA5)
Fatal Alcohol Involvement Crash	A fatal crash is alcohol-related or alcohol-involved if either a driver or a non motorist (usually a pedestrian) had a measurable or estimated blood alcohol concentration (BAC) of 0.01 grams per deciliter (g/dl) or above. (NHTSA3)
Fatal Crash	A police-reported crash involving a motor vehicle in transport on a trafficway in which at least one person dies within 30 days of the crash. (NHTSA3) (NHTSA4)
Fatal Crash (Highway)	A police-reported crash involving a motor vehicle in transport on a trafficway in which at least 1 person dies within 30 days of the crash as a result of that crash.
Fatal Injury	Any injury which results in death within 30 days of the accident. (FHWA5) (NTSB1) (NTSB2)
Fatal Injury (Air)	Any injury that results in death within 30 days of the accident.
Fatal Plus Nonfatal Injury Accidents	The sum of all fatal accidents and nonfatal-injury accidents. (FHWA5)
Fatality	For purposes of statistical reporting on transportation safety, a fatality is considered a death due to injuries in a transportation crash, accident, or incident that occurs within 30 days of that occurrence.
Fatality (Rail)	1) Death of any person from an injury within 30 days of the accident or incident (may include nontrain accidents or incidents); or 2) death of a railroad employee from an occupational illness within 365 days after the occupational illness was diagnosed by a physician.
Fatality (Recreational Boating)	All deaths (other than deaths by natural causes) and missing persons resulting from an occurrence that involves a vessel or its equipment.
Fatality (Transit)	A transit-caused death confirmed within 30 days of a transit incident. Incidents include collisions, derailments, personal casualties, and fires associated with transit agency revenue vehicles, transit facilities on transit property, service vehicles, maintenance areas, and rights-of-way.
Fatality (Water)	All deaths and missing persons resulting from a vessel casualty.
Fatality Rate	The average number of fatalities which occurred per accident or per one hundred accidents. (FHWA2)
Fatality/Injury	Refers to the average number of fatalities and injuries which occurred per one hundred accidents. Frequently used as an index of accident severity. (FHWA4)
Fault of Operator	Speeding; overloading; improper loading, not properly seating occupants of boat; no longer lookout; carelessness; failure to heed weather warnings; operating in a congested area; not observing the Rules of the Road; unsafe fueling practices; lack of experience; ignorance of aids to navigation; lack of caution in an unfamiliar area of operation; improper installation or maintenance of hull, machinery or equipment; poor judgment; recklessness; overpowering the boat; panic; proceeding in an unseaworthy craft; operating a motorboat near persons in the water; staring engine with clutch engaged or throttle advanced; irresponsible boat handling such as quick, sharp turns. (USCG2)
Feathered Propeller	A propeller whose blades have been rotated so that the leading and trailing edges are nearly parallel with the aircraft flight path to stop or minimize drag and engine rotation. Normally used to indicate shutdown of a reciprocating or turboprop engine due to malfunction. (FAA4)
Federal Aid Secondary Highway System	This existed prior to the ISTEA [Intermodal Surface Transportation Efficiency Act] of 1991 and included rural collector routes. (FHWA5)
Federal Aid Urban Highway System	This existed prior to the ISTEA [Intermodal Surface Transportation Efficiency Act] of 1991 and included urban arterial and collector routes, exclusive of urban extensions of the Federal-Aid Primary system. (FHWA5)
Federal Aviation Administration (FAA)	FAA provides a safe, secure, and efficient global aerospace system that contributes to national security and the promotion of US aerospace safety. As the leading authority in the international aerospace community, FAA is responsive to the dynamic nature of customer needs, economic conditions, and environmental concerns.
Federal Aviation Administration (FAA)	Formerly the Federal Aviation Agency, the Federal Aviation Administration was established by the Federal Aviation Act of 1958 (49 U.S.C. 106) and became a component of the Department of Transportation in 1967 pursuant to the Department of Transportation
Federal Aviation Regulations (FAR)	The set of regulatory obligations contained in Title 14 of the Code of Federal Regulations which FAA is charged to enforce in order to promote the safety of civil aviation both domestically and internationally. (FAA1)
Federal Boating Safety Act (FBSA)	Enacted by Congress on 10 August 1971, it gave the Coast Guard the authority to establish comprehensive boating safety programs, authorized the establishment of national construction and performance standards for boats and associated equipment and created a more flexible regulatory authority concerning the use of boats and associated equipment. Amended by the Recreational Boating Safety and Facilities Improvement Act of 1980 aka The Recreational Boating Fund Act of 1980 (The Biaggi Act) which provided financial assistance, in part through motorboat fuel taxes, for State recreational boating safety programs. Now recodified as Chapter 43 of Title 46, United States Code. (USCG1)
Federal Energy Regulatory Commission (FERC)	The federal agency with jurisdiction over, among other things, gas pricing, oil pipeline rates, and gas pipeline certification.
Federal Finance System (FFS)	An automated accounting system used by the DOI for tracking obligations and expenditures.
Federal Hazardous Material Transportation Law	49 U.S.C. 5101 et seq. (49CFR171)
Federal Highway Administration (FHWA)	A branch of the US Department of Transportation that administers the federal-aid Highway Program, providing financial assistance to states to construct and improve highways, urban and rural roads, and bridges. The FHWA also administers the Federal Lands Highway Program, including survey, design, and construction of forest highway system roads, parkways and park roads, Indian reservation roads, defense access roads, and other Federal lands roads. The Federal agency within the U.S. Department of Transportation responsible for administering the Federal-Aid Highway Program. Became a component of the Department of Transportation in 1967 pursuant to the Department of Transportation Act (49 U.S.C. app. 1651 note). It administers the highway transportation programs of the Department of Transportation under pertinent legislation
Federal Lands Highway Program (FLHP)	Provides funds to construct roads and trails within (or, in some cases, providing access to) Federal lands. There are four categories of FLHP funds: Indian Reservation Roads, Public Lands Highways, Park Roads and Parkways, and Refuge Roads. Funds available to the US Forest Service may be used for forest development roads and trails. To be eligible for funding, projects must be open to the public and part of an approved Federal land management agency general management plan. 23 U.S.C. 204.
Federal Motor Carrier Safety Regulations (FMCSR)	The regulations are contained in the Code of Federal Regulations, Title 49, Chapter III, Subchapter B. (FHWA2) (FHWA4)
Federal Power Act	Enacted in 1920, and amended in 1935, the Act consists of three parts. The first part incorporated the Federal Water Power Act administered by the former Federal Power Commission, whose activities were confined almost entirely to licensing non-Federal hydroelectric projects. Parts II and III were added with the passage of the Public Utility Act. These parts extended the Act's jurisdiction to include regulating the interstate transmission of electrical energy and rates for its sale as wholesale in interstate commerce. The Federal Energy Regulatory Commission is now charged with the administration of this law. (DOE5)
Federal Railroad Administration (FRA)	The purpose of the Federal Railroad Administration is to promulgate and enforce rail safety regulations, administer railroad financial assistance programs, conduct research and development in support of improved railroad safety and national rail transportation policy, provide for the rehabilitation of Northeast corridor rail passenger service, and consolidate government support of rail transportation activities. The FRA was created pursuant to section 3(e)(1) of the Department of Transportation Act of 1966 (49 U.S.C. app. 1652). (OFR1)
Federal Register	Daily publication which provides a uniform system for making regulations and legal notices issued by the Executive Branch and various departments of the Federal government available to the public. (USCG1)
Federal Transit Administration (FTA)	A branch of the US Department of Transportation that is the principal source of federal financial assistance to America's communities for planning, development, and improvement of public or mass transportation systems. FTA provides leadership, technical assistance, and financial resources for safe, technologically advanced public transportation to enhance mobility and accessibility, to improve the Nation's communities and natural environment, and to strengthen the national economy. (Formerly the Urban Mass Transportation Administration) operates under the authority of the Federal Transit Act, as amended (49 U.S.C. app. 1601 et seq.). The Federal Transit Act was repealed on July 5, 1994, and the Federal transit laws were codified and re-enacted as chapter 53 of Title 49, United States Code. The Federal Transit Administration was established as a component of the Department of Transportation by section 3 of Reorganization Plan No. 2 of 1968 (5 U.S.C. app.), effective July 1, 1968. The missions of the Administration are 1) to assist in the development of improved mass transportation facilities, equipment, techniques, and methods, with the cooperation of mass transportation companies both public and private. 2) to encourage the planning and establishment of areawide urban mass transportation systems needed for economical and desirable urban development, with the cooperation of mass transportation companies both public and private. and 3) to provide assistance to State and local governments and their instrumentalities in financing such systems, to be operated by public or private mass transportation companies as determined by local needs; and 4) to provide financial assistance to State and local governments to help implement national goals relating to mobility for elderly persons, persons with disabilities, and economically disadvantaged persons. (OFR1)
Federal Water Pollution Control Act (FWPCA)	Law passed in 1970 and amended in 1972 giving the Coast Guard a mandate to develop, among other things, marine sanitation device regulations. (USCG1)
Federal-aid Highway Program (FAHP)	An umbrella term for most of the Federal programs providing highway funds to the States. This is not a term defined in law. As used in this document, FAHP is comprised of those programs authorized in Titles I and V of TEA-21 that are administered by FHWA.
Federal-Aid Highways	Those highways eligible for assistance under Title 23 U.S.C. except those functionally classified as local or rural minor collectors. (23CFR500)
Federal-Aid Primary Highway System	The Federal-Aid Highway System of rural arterials and their extensions into or through urban areas in existence on June 1, 1991, as described in 23 U.S.C. 103b) in effect at that time. (23CFR658)
Feeder Bus	A bus service that picks up and delivers passengers to a rail rapid transit station or express bus stop or terminal. (APTA1)
Feeder Fix	The fix depicted on Instrument Approach Procedure Charts which establishes the starting point of the feeder route. (FAA4)
Feeder Route	A route depicted on instrument approach procedure charts to designate routes for aircraft to proceed from the en route structure to the initial approach fix (IAF). (FAA4)
Feeder Vessel	A vessel which transfers containers to a "mother ship" for an ocean voyage. (MARAD2)
Ferries	Establishments primarily engaged in operating ferries for the transportation of passengers or vehicles. (BOC1)
Ferry Boat	A boat providing fixed-route service across a body of water. (APTA1)
Ferry Crossing	Route used to transport traffic between two points separated by water. (DOI3)
Ferry Flight	A flight for the purpose of 1) Returning an aircraft to base. 2) Delivering an aircraft from one location to another. 3) Moving an aircraft to and from a maintenance base. Ferry flights, under certain conditions, may be conducted under terms of a special flight permit. (FAA4)
Ferry Vessel	A vessel which is limited in its use to the carriage of deck passengers or vehicles or both, operates on a short run on a frequent schedule between two points over the most direct water route, other than in ocean or coastwise service, and is offered as a public service of a type normally attributed to a bridge or tunnel. (49CFR171)
Ferryboat (Transit)	Vessels that carry passengers and/or vehicles over a body of water. Generally steam or diesel-powered, ferryboats may also be hovercraft, hydrofoil, and other high-speed vessels. The vessel is limited in its use to the carriage of deck passengers or vehicles or both, operates on a short run on a frequent schedule between two points over the most direct water routes other than in ocean or coastwise service, and is offered as a public service of a type normally attributed to a bridge or tunnel.
Ferryboats	Vessels for carrying passengers and/or vehicles over a body of water. The vessels are generally steam or diesel-powered conventional ferry vessels. They may also be hovercraft, hydrofoil and other high speed vessels. (FTA1)
Fiberglass (Plastic) Hull	Hulls of fiber reinforced plastic. The laminate consists of two basic components, the reinforcing material (glass filaments) and the plastic or resin in which it is embedded. (USCG2)
Field and Gathering Pipelines	A network of pipelines (mains) transporting natural gas from the individual wells to a compressor station, processing point, or main trunk pipeline. (AGA1)
Field Area	(See also Pool) A geographic area encompassing two or more pools that have a common gathering and metering system, the reserves of which are reported as a single unit. This concept applies primarily to the Appalachian region. (DOE5)
Field Separation Facility	A surface installation designed to recover lease condensate from a produced natural gas stream usually originating from more than one lease and managed by the operator of one or more of these leases. (DOE5)
Fifth Wheel	A device mounted on a truck tractor or similar towing vehicle (e.g., converter dolly) which interfaces with and couples to the upper coupler assembly of a semitrailer. (49CFR393) (ATA2)
Filed	Normally used in conjunction with flight plans, meaning a flight plan has been submitted to Air Traffic Control (ATC). (FAA4)
Filed En Route Delay	Any of the following preplanned delays at points/areas along the route of flight which require special flight plan filing and handling techniques. 1) Terminal Area Delay. A delay within a terminal area for touch and go, low approach, or other terminal area activity. 2) Special Use Airspace Delay. A delay within a Military Operating Area, Restricted Area, Warning Area, or Air Traffic Control (ATC) Assigned Airspace. 3) Aerial Refueling Delay. A delay within an Aerial Refueling Track or Anchor. (FAA4)
Fill Material	Any material used for the primary purpose of replacing an aquatic area with dry land or of changing the bottom elevation of a body of water. (TNDOT1)
Final	Commonly used to mean that an aircraft is on the final approach course or is aligned with a landing area. (FAA4)
Final Approach	That part of an instrument approach procedure which commences at the specified final approach fix or point, or where such a fix or point is not specified, 1) At the end of the last procedure turn, base turn or inbound turn of a racetrack procedure, if specified; or 2) At the point of interception of the last track specified in the approach procedure; and ends at a point in the vicinity of an aerodrome from which a) A landing can be made; or b) A missed approach procedure is initiated. (FAA4)
Final Approach Course	A published Microwave Landing System (MLS) course, a straight line extension of a localizer, a final approach radial/bearing, or a runway centerline all without regard to distance. (FAA4)
Final Approach Fix (FAF)	The fix from which the final approach Instrument Flight Rule (IFR) to an airport is executed and which identifies the beginning of the final approach segment. It is designated on Government charts by the Maltese Cross symbol for nonprecision approaches and the lightning bolt symbol for precision approaches; or when Air Traffic Control (ATC) directs a lower-than-published Glideslope/path Intercept Altitude, it is the resultant actual point of the glideslope/path intercept. (FAA4)
Final Approach Point (FAP)	The point, applicable only to a nonprecision approach with no depicted Final Approach Fix (FAF) (such as an on-airport VOR), where the aircraft is established inbound on the final approach course from the procedure turn and where the final approach descent may be commenced. The final approach point (FAP) serves as the FAF and identifies the beginning of the final approach segment. (FAA4)
Final Approach Segment	That segment of an instrument approach procedure in which alignment and descent for landing are accomplished. (FAA4)
Final Controller	(See also Air Traffic Control Specialist; Controller) The controller providing information and final approach guidance during PAR and Airport Surveillance Radar (ASR) approaches utilizing radar equipment. (FAA4)
Final Monitor Aid	A high resolution color display that is equipped with the controller alert system hardware/software which is used in the precision runway monitor (PRM) system. The display includes alert algorithms providing the target predictors, a color change alert when a target penetrates or is predicted to penetrate the no transgression zone (NTZ), a color change alert if the aircraft transponder becomes inoperative, synthesized voice alerts, digital mapping and like features contained in the PRM system. (FAA4)
Financial analysis	Estimating costs, establishing a revenue baseline, comparing revenues with costs and evaluating new revenue sources.
Financial Capacity	Refers to the ISTEA requirement that an adequate financial plan for funding and sustaining transportation improvements be in place prior to programming Federally-funded projects. Generally refers to the stability and reliability of revenue in meeting proposed costs.
Financial Planning	The process of defining and evaluating funding sources, sharing the information, and deciding how to allocate the funds.
Financial Programming	A short-term commitment of funds to specific projects identified in the regional Transportation Improvement Program (see TIP).
Fine Particulates	Particulate matter less than 2.5 microns in size (PM-2.5). A micron is one millionth of a meter. See "Particulate matter" below.
Finished Aviation Gasoline	(See also Gasoline) All special grades of gasoline for use in aviation reciprocating engines, as given in American Society for Testing and Materials (ASTM) Specification D910 and Military Specification MIL-G-5572. Excludes blending components that will be used for blending or compounding into finished aviation gasoline. (DOE3) (DOE5)
Finished Gasohol Motor Gasoline	(See also Gasohol, Gasoline) A blend of finished motor gasoline (leaded or unleaded) and alcohol (generally ethanol, but sometimes methanol) in which 10 percent or more of the product is alcohol. (DOE3) (DOE5)
Finished Gasoline	See also Gasoline.
Finished Leaded Gasoline	Contains more than 0.05 gram of lead per gallon or more than 0.005 gram of phosphorus per gallon. Premium and regular grades are included, depending on the octane rating. Includes leaded gasohol. Blendstock is excluded until blending has been completed. Alcohol that is to be used in the blending of gasohol is also excluded. (DOE3) (DOE5)
Finished Leaded Premium Motor Gasoline	Motor gasoline having an antiknock index, calculated as (R+M)/2, greater than 90 and containing more than 0.05 gram of lead per gallon or more than 0.005 gram of phosphorus per gallon. (DOE3) (DOE5)
Finished Leaded Regular Motor Gasoline	Motor gasoline having an antiknock index, calculated as (R+M)/2, greater than or equal to 87 and less than or equal to 90 and containing more than 0.05 gram of lead or 0.005 gram of phosphorus per gallon. (DOE3) (DOE5)
Finished Motor Gasoline	1) A complex mixture of relatively volatile hydrocarbons, with or without small quantities of additives, blended to form a fuel suitable for use in spark-ignition engines. Specification for motor gasoline, as given in American Society for Testing and Materials (ASTM) Specification D439-88 or Federal Specification VV-G-1690B, include a boiling range of 122 degrees to 158 degrees Fahrenheit at the 10-percent point to 365 degrees to 374 degrees Fahrenheit at the 90-percent point and a Reid vapor pressure range from 9 to 15 psi. "Motor gasoline" includes finished leaded gasoline, finished unleaded gasoline, and gasohol. Blendstock is excluded until blending has been completed. (Alcohol that is to be used in the blending of gasohol is also excluded.) 2) Motor gasoline that is not included in the reformulated or oxygenated categories. (DOE3) (DOE5)
Finished Unleaded Gasoline	Contains not more than 0.05 gram of lead per gallon and not more than 0.005 gram of phosphorus per gallon. Premium and regular grades are included, depending on the octane rating. Includes unleaded gasohol. Blendstock is excluded until blending has been completed. Alcohol that is to be used in the blending of gasohol is also excluded. (DOE3) (DOE5)
Finished Unleaded Midgrade Motor Gasoline	Motor gasoline having an antiknock index, calculated as (R+M)/2, greater than or equal to 88 and less than or equal to 90 and containing not more than 0.05 gram of phosphorus per gallon. (DOE3) (DOE5)
Finished Unleaded Premium Motor Gasoline	Motor gasoline having an antiknock index, calculated as (R+M)/2, greater than 90 and containing not more than 0.05 gram of lead or 0.005 gram of phosphorus per gallon. (DOE3) (DOE5)
Finished Unleaded Regular Motor Gasoline	Motor gasoline having an antiknock index, calculated as (R+M)/2, of 87 containing not more than 0.05 gram of lead per gallon and not more than 0.005 gram of phosphorus per gallon. (DOE3) (DOE5)
Fire	Uncontrolled combustion by flame or smoke resulting in evidence of charring, melting, or other evidence of ignition. (FTA1)
Fire or Violent Rupture	(See also Flash Resistant) An accident/incident caused by combustion or violent release of material carried by or transported by rail. Examples of this type include fuel and electrical equipment fires; crankcase explosions; and, violent release of liquified petroleum or anhydrous ammonia. (FRA2)
Fire Resistant	1) With respect to sheet or structural members means the capacity to withstand the heat associated with fire at least as well as aluminum alloy in dimensions appropriate for the purpose for which they are used; and 2) With respect to fluid-carrying lines, fluid system parts, wiring, air ducts, fittings, and powerplant controls, means the capacity to perform the intended functions under the heat and other conditions likely to occur when there is a fire at the place concerned. (14CFR1)
Fire/Explosion, Fuel	Accidental combustion of vessel fuel, liquids, including their vapors, or other substances, such as wood or coal. (USCG2)
Fire/Explosion, Other	Accidental burning or explosion of any material on board except vessel fuels or their vapors. (USCG2)
Firefighting Vehicle	A vehicle designed exclusively for the purpose of fighting fires. (49CFR571)
Fireproof	1) With respect to materials and parts used to confine fire in a designated fire zone, means the capacity to withstand at least as well as steel in dimensions appropriate for the purpose for which they are used, the heat produced when there is a severe fire of extended duration in that zone; and 2) With respect to other materials and parts, means the capacity to withstand the heat associated with fire at least as well as steel in dimensions appropriate for the purpose for which they are used. (14CFR1)
Firewall	A budgetary device separating certain Federal spending within the discretionary spending category from other spending in the discretionary category. Spending for programs with firewalls may not be reduced in order to increase spending for other discretionary programs. The TEA-21 establishes, for fiscal years 1999-2003, a firewall to protect highway and highway safety spending and a firewall to protect transit spending.
First Call On Berth Privilege	See Preferential Assignment.
First Class Passenger Revenue	Revenues from the air transportation of passengers moving at either standard fares, premium fares, or at reduced fares not predicated upon the use of aircraft space specifically separated from first class, and for whom standard or premium quality services are provided. (BTS4)
First Class Service	Transport service established for the carriage of passengers moving at either standard fares or premium fares, or at reduced fares not predicated upon the operation of specifically allocated aircraft space, and for whom standard or premium quality services are provided. (BTS5)
First Harmful Event	A first harmful event is the first event during a traffic accident that causes an injury (fatal or nonfatal) or property damage. (FHWA5)
First Tier Center	The air route traffic control center immediately adjacent to the impacted center. (FAA4)
Fiscal Constraint	Making sure that a given program or project can reasonably expect to receive funding within the time allotted for its implementation.
Fiscal Year (FY)	The yearly accounting period beginning October 1 and ending September 30 of the subsequent calendar year. Fiscal years are denoted by the calendar year in which they end (e.g. FY 1991 began October 1, 1990, and ended September 30, 1991).
Fishy Back	The movement of loaded truck trailers by barge or ferry. (TNDOT1)
Fix	A geographical position determined by visual reference to the surface, by reference to one or more radio navigational aids (NAVAIDs), by celestial plotting, or by another navigational device. (FAA4)
Fix Balancing	A process whereby aircraft are evenly distributed over several available arrival fixes reducing delays and controller workload. (FAA4)
Fixed Collision Barrier	A flat, vertical, unyielding surface with the following characteristics 1) The surface is sufficiently large that when struck by a tested vehicle, no portion of the vehicle projects or passes beyond the surface; 2) The approach is a horizontal surface that is large enough for the vehicle to attain a stable attitude during its approach to the barrier, and that does not restrict vehicle motion during impact; 3) When struck by a vehicle, the surface and its supporting structure absorb no significant portion of the vehicle's kinetic energy, so that a performance requirement described in terms of impact with a fixed collision barrier must be met no matter how small an amount of energy is absorbed by the barrier. (49CFR571)
Fixed Crane	A crane whose principal structure is mounted on a permanent or semipermanent foundation. (TNDOT1)
Fixed Dam	A dam which does not permit the passage of marine traffic and requires the use of a lock in contrast to movable dams which, during periods of high water, are lowered to allow traffic to pass directly over the dam. Also, any dam that has a fixed height without adjustment such as a concrete spillway throughout the length of the dam exclusive of the lock chamber. (TNDOT1)
Fixed Guideway System	A system of vehicles that can operate only on its own guideway constructed for that purpose (e.g., rapid rail, light rail). Federal usage in funding legislation also includes exclusive right-of-way bus operations, trolley coaches and ferryboats as "fixed guideway" transit. (APTA1)
Fixed Object	Stationary structures or substantial vegetation attached to the terrain. (NHTSA1) (NHTSA3)
Fixed Operating Cost	In reference to passenger car operating cost, refers to those expenditures that are independent of the amount of use of the car, such as insurance costs, fees for license and registration, depreciation and finance charges. (DOE6)
Fixed Route	Service provided on a repetitive, fixed-schedule basis along a specific route with vehicles stopping to pick up and deliver passengers to specific locations; each fixed-route trip serves the same origins and destinations, unlike demand response and taxicabs. (APTA1)
Fixed Route System	A system of transporting individuals (other than by aircraft), including the provision of designated public transportation service by public entities and the provision of transportation service by private entities, including, but not limited to, specified public transportation service, on which a vehicle is operated along a prescribed route according to a fixed schedule. (49CFR37)
Fixed-Route	Term applied to transit service that is regularly scheduled and operates over a set route; usually refers to bus service.
Flag	A warning device incorporated in certain airborne navigation and flight instruments indicating that 1) Instruments are inoperative or otherwise not operating satisfactorily, or 2) Signal strength or quality of the received signal falls below acceptable values. (FAA4)
Flag Drop Charge	The charge for an initial distance (usually specified by regulation) for taxi service. It is actually the minimum fare. (TRB1)
Flagman's Signals	A red flag by day and a white light at night, and a specified number of torpedoes and fusees as prescribed in the railroad's operating rules. (49CFR218)
Flame Resistant	Not susceptible to combustion to the point of propagating a flame, beyond safe limits, after the ignition source is removed. (14CFR1)
Flameout	Unintended loss of combustion in turbine engines resulting in the loss of engine power. (FAA4)
Flammable	With respect to a fluid or gas, means susceptible to igniting readily or to exploding. (14CFR1)
Flanking Buoy	Buoy tied to the corner of a tow so pilot can tell when tow has been checked. (TNDOT1)
Flanking Maneuver	Maneuvering action of a tow (when downbound) approaching at an angle (usually 30 to 45 degrees) at bridges or locks or in sharp bends. Only the current is utilized for headway, and the engines and rudders are used to maintain the angle until just before the lead barges reach the bridge span, at which time the engines are backed and the head of the tow is swung gently in line with the opening. Then full power is applied to drive through the opening. This is the safest way that a heavy tow can make tight passages. (TNDOT1)
Flanking Rudder	A rudder installed forward of the screw, used for maneuvering when the propellers are turning a stem regardless of the direction of actual movement of the towboat. Also called "backing rudders." (TNDOT1)
Flap Extended Speed	The highest speed permissible with wing flaps in a prescribed extended position. (14CFR1)
Flash Resistant	(See also Fire or Violent Rupture) Not susceptible to burning violently when ignited. (14CFR1)
Flasher	In rail systems, the flashing light at railroad grade crossings that warns motorists, bicyclists, and pedestrians of approaching trains. (TRB1)
Flat	A small barge with flat top used for transporting fuel or other miscellaneous cargo. (TNDOT1)
Flat Bottom	Flatbed. (ATA1)
Flat Car	A rail car without a roof and walls. (MARAD2)
Flat Face	Cab over engine. (ATA1)
Flat Pool	The normal stage of water in the area between two dams that is to be maintained by design when little or no water is flowing; hence the pool flattens out. (TNDOT1)
Flat Rate Manual	A manual published by an equipment manufacturer or an independent publisher that indicates the length of time required for performing specific mechanical tasks such as installing a clutch. Normally, the costs of parts required for a specific job are also listed. (GSA2)
Flatbed	Truck or trailer without sides and top. (ATA1)
Flatboat	A rectangular, flat bottomed boat used on the western rivers during the 18th and 19th centuries. (TNDOT1)
Fleet	The vehicles in a transit system. Usually, "fleet" refers to highway vehicles and "rolling stock" to rail vehicles. (TRB1)
Fleet Management Center (FMC) (FMC)	A formally approved element of the Interagency Fleet Management System (IFMS) responsible for the administrative control of Interagency Fleet Management System (IFMS) vehicles in a specified geographic area as defined in the determination that is approved by the Administrator of General Services. (GSA2)
Fleet Management Subcenter	A formally approved element of the Interagency Fleet Management System (IFMS) Fleet Management Center physically detached from the central or main Fleet Management Center. (GSA2)
Fleet Management System (FMS)	The automated inventory and control system used by the Interagency Fleet Management System (IFMS) to track vehicle assignments, vehicle utilization, and provide direct input to the Finance Division to bill customer agencies for the use of IFMS vehicles. (GSA2)
Fleet Vehicles	1) Private fleet vehicles ideally, a vehicle could be classified as a member of a fleet if it is operated in mass by a corporation or institution, operated under unified control, or used for non-personal activities; however, the definition of a fleet is not consistent throughout the fleet industry. Some companies make a distinction between cars that were bought in bulk rather than singularly, or whether they are operated in bulk, as well as the minimum number of vessels that constitute a fleet (i.e. 4 or 10); 2) Government fleet vehicles includes vehicles owned by all federal (GSA) state, county, city, and metro units of government, including toll road operations. (DOE6)
Fleeting	Storing of barges (loaded or unloaded) until they can be moved to the unloading area or until the owner can pick them up. (TNDOT1)
Flight Advisory Service	(See also Flight Watch) A service specifically designed to provide, upon pilot request, timely weather information pertinent to his type of flight, intended route of flight, and altitude. The flight service stations providing this service are listed in the Airport/Facility Directory. (FAA4)
Flight Check	(See also Flight Inspection) A call-sign prefix used by Federal Aviation Administration (FAA) aircraft engaged in flight inspection/certification of navigational aids and flight procedures. The word "recorded" may be added as a suffix; (e.g., "Flight Check 320 recorded" to indicate that an automated flight inspection is in progress in terminal areas). (FAA4)
Flight Crew Member	A pilot, flight engineer, or flight navigator assigned to duty in an aircraft during flight time. (14CFR1)
Flight Equipment	The total cost of property and equipment of all types used in the in-flight operations of aircraft and construction work in progress. (BTS4)
Flight Information Region (FIR) (FIR)	An airspace of defined dimensions within which Flight Information Service and Alerting Service are provided. (FAA4)
Flight Information Service	A service provided for the purpose of giving advice and information useful for the safe and efficient conduct of flights. (FAA4) (FAA8)
Flight Inspection	(See also Flight Check) Inflight investigation and evaluation of a navigational aid to determine whether it meets established tolerances. (FAA4)
Flight Level	(See also Cardinal Altitude) A level of constant atmospheric pressure related to a reference datum of 29.92 inches of mercury. Each is stated in three digits that represent hundreds of feet. For example, flight level 250 represents a barometric altimeter indication of 25,000 feet; flight level 255, an indication of 25,500 feet. (14CFR1)
Flight Line	A term used to describe the precise movement of a civil photogrammetric aircraft along a predetermined course(s) at a predetermined altitude during the actual photographic run. (FAA4)
Flight Management System	A computer system that uses a large data base to allow routes to be preprogrammed and fed into the system by means of a data loader. The system is constantly updated with respect to position accuracy by reference to conventional navigation aids. The sophisticated program and its associated data base insures that the most appropriate aids are automatically selected during the information update cycle. (FAA4)
Flight Management System Procedure	An arrival, departure, or approach procedure developed for use by aircraft with a slant (/G) equipment suffix. (FAA4)
Flight Path	(See also Bearing, Course) A line, course, or track along which an aircraft is flying or intended to be flown. (FAA4) (FAA8)
Flight Plan	Specified information, relating to the intended flight of an aircraft, that is filed orally or in writing with air traffic control. (14CFR1) (FAA2) (FAA5) (FAA14)
Flight Plan Area	The geographical area assigned by regional air traffic divisions to a flight service station for the purpose of search and rescue for Visual Flight Rule (VFR) aircraft, issuance of NOTAMs, pilot briefing, in-flight services, broadcast, emergency services, flight data processing, international operations, and aviation weather services. Three letter identifiers are assigned to every flight service station and are annotated in AFD's and Order 7350.6 as tie-in-facilities. (FAA4)
Flight Recorder	A general term applied to any instrument or device that records information about the performance of an aircraft in flight or about conditions encountered in flight. Flight recorders may make records of airspeed, outside air temperature, vertical acceleration, engine RPM, manifold pressure, and other pertinent variables for a given flight. (FAA4)
Flight Service Station (FSS)	Air traffic facilities which pilot briefing, en route communications, and VFR search and rescue services; assist lost aircraft and aircraft in emergency situations; relay ATC clearances; originate Notices to Airmen, broadcast aviation weather and NAS information; receive and process IFR flight plans, monitor radio Navigation Aids (NAVAIDS). In addition, at selected locations, FSSs take weather observations, issue airport advisories, and advise Customs and Immigration of transborder flight. (FAA2) (FAA4) (FAA8) (FAA13)
Flight Services	The sum of flight plans originated and pilot briefs, multiplied by two, plus the number of aircraft contacted. (FAA2)
Flight Stage	The operation of an aircraft from take-off to landing. (BTS5) (BTS6)
Flight Standards District Office	An Federal Aviation Administration (FAA) field office serving an assigned geographical area and staffed with Flight Standards personnel who serve the aviation industry and the general public on matters relating to the certification and operation of air carrier and general aviation aircraft. Activities include general surveillance of operational safety, certification of airmen and aircraft, accident prevention, investigation, enforcement, etc. (FAA4)
Flight Test	A flight for the purpose of 1) Investigating the operation/flight characteristics of an aircraft or aircraft component. 2) Evaluating an applicant for a pilot certificate or rating. (FAA4)
Flight Time	The time from the moment the aircraft first moves under its own power for the purpose of flight until the moment it comes to rest at the next point of landing. Also known as block-to-block time. (14CFR1)
Flight Visibility	The average forward horizontal distance, from the cockpit of an aircraft in flight, at which prominent unlighted objects may be seen and identified by day and prominent lighted objects may be seen and identified by night. (14CFR1)
Flight Watch	(See also Flight Advisory Service) A shortened term for use in air-ground contacts to identify the flight service station providing En Route Flight Advisory Service (e.g., "Oakland Flight Watch"). (FAA4)
Float	Flatbed semitrailer. (ATA1)
Float Light	A 10 foot wooden platform mounted on pontoons supporting a battery-operated light. Used exclusively on the Upper Mississippi River in a certain area. (TNDOT1)
Floater	Driver without a steady job. (ATA1)
Floating Crane	A crane mounted on a barge or pontoon which can be towed or self-propelled from place to place. (TNDOT1)
Floating Pin	A mooring pin or timberhead attached to a floating tank in a lock chamber set in a guided recess in the lock walls, for mooring tows within the lock chamber whereby a short mooring line suffices without an attendant. (TNDOT1)
Floating the Gears	Shifting gears without using the clutch. (ATA1)
Floats	Large single, instead of dual tires. (ATA1)
Flood Plain	An area which is subject to periodic flooding. (DOI4)
Flood Stage	Condition of the river when it rises above a stage predetermined by the Corps of Engineers to be designated as flood stage. Also, the stage at which some part of the main bank may be over flowed, but not necessarily all of it. (TNDOT1)
Floodgate	(See also Gate; Tidegate) Gate placed across/along a channel to control floodwater or a gate across a roadway in levee. (DOI3)
Flooding	Filling with water, regardless of method of ingress, but retaining sufficient buoyancy to remain on the surface. (USCG2)
Flow Control	Measures designed to adjust the flow of traffic into a given airspace, along a given route, or bound for a given aerodrome (airport) so as to ensure the most effective utilization of the airspace. (FAA4)
Fly Heading (Degrees)	Informs the pilot of the heading he should fly. The pilot may have to turn to, or continue on, a specific compass direction in order to comply with the instructions. The pilot is expected to turn in the shorter direction to the heading unless otherwise instructed by ATC. (FAA4)
Flyaway Value	Includes the cost of the airframe, engines, electronics, communications, armament, and other installed equipment. (AIA1)
Flyer	A run in which the driver takes a trailer to a distant terminal, leaves it there and immediately pulls another trailer back to his home terminal. (ATA1)
Flying (Other Work Use)	Any aircraft used for construction work (not included under Part 135), helicopter, hoist, towing gliders, or parachuting. (FAA2)
Flying (Other)	Any other use of an aircraft not included above (experimentation, R&D, testing, demonstration, government). (FAA2)
Flying Operations Expenses	Expenses incurred directly in the in-flight operation of aircraft and expenses related to the holding of aircraft and aircraft operational personnel in readiness for assignment for an in-flight status. (BTS4)
Flying Orders	Trip instructions issued to a driver by his dispatcher. (ATA1)
Foamed Buoy	A buoy whose interior is filled with styrofoam for the purpose of improving flotation when in a damaged condition. (TNDOT1)
For Hire	Refers to a vehicle operated on behalf of or by a company that provides transport services to its customers. (BOC3)
For Hire Carrier	Carrier that provides transportation service to the public on a fee basis.
Force Majeure	The title of a standard clause found in marine contracts exempting the parties for non-fulfillment of their obligations by reasons of occurrences beyond their control, such as earthquakes, floods, or war. (TNDOT1)
Ford	The shallow part of a river which can be easily crossed. (DOI4)
Fore and Aft	The direction on a vessel parallel to the center line. (MARAD2)
Fore and Aft Line	A line used to secure two barges end to end. (TNDOT1)
Fore Bay	An enclosure of the river, usually above a dam. (TNDOT1)
Foreign	Outside the fifty United States and the District of Columbia. (49CFR383)
Foreign Air Carrier	(See also Foreign Flag Air Carrier) Any person other than a citizen of the United States, who undertakes directly, by lease or other arrangement, to engage in air transportation. (14CFR1)
Foreign Air Commerce	The carriage by aircraft of persons or property for compensation or hire, or the carriage of mail by aircraft, or the operation or navigation of aircraft in the conduct or furtherance of a business or vocation, in commerce between a place in the United States and any place outside thereof; whether such commerce moves wholly by aircraft or partly by aircraft and partly by other forms of transportation. (14CFR1)
Foreign Air Transportation	The carriage by aircraft of persons or property as a common carrier for compensation or hire, or the carriage of mail by aircraft, in commerce between a place in the United States and any place outside of the United States, whether that commerce moves wholly by aircraft or partly by aircraft and partly by other forms of transportation. (14CFR1)
Foreign Current	A term applied to stray electric currents which may affect a signaling system, but which are not a part of the system. (49CFR236)
Foreign Exchange Gains and Losses	Gains or losses resulting from nonroutine abnormal changes in the rates of foreign exchange. (BTS4)
Foreign Flag Air Carrier	(See also Foreign Air Carrier) An air carrier other than a U.S. flag air carrier in international air transportation. "Foreign air carrier" is a more inclusive term than "foreign flag air carrier," including those non-U.S. air carriers operating solely within their own domestic boundaries. In practice, the two terms are used interchangeably. (FAA2) (FAA14)
Foreign Fleet	All reportable agency owned motor vehicles, operated outside any State, Commonwealth, Territory or possession of the United States. (GSA1)
Foreign Freight	Movements between the United States and foreign countries and between Puerto Rico, the Virgin Islands, and foreign countries. Trade between U.S. territories and possessions (e.g. Guam, Wake, American Samoa) and foreign countries is excluded. Traffic to or from the Panama Canal Zone is included. (DOE6)
Foreign Freight Forwarder	An independent business which makes shipments for exporters for a fee. (TNDOT1)
Foreign Mail	Mail transported outside the United States by U.S. flag carriers for a foreign government. (BTS5) (FAA2) (FAA15)
Foreign Trade	The exchange of waterborne commodity movements (imports and exports) between the United States and its territory, and foreign countries. (MARAD1)
Foreign Trade Zone (FTZ)	A specially designated area, in or adjacent to a U.S. Customs Port Of Entry, which is considered to be outside the Customs Territory of the U.S.
Foreshore	The part of a seashore between high-water and low-water marks. (DOI3)
Forestall	As applied to an automatic train stop or train control device, to prevent an automatic brake application by operation of an acknowledging device or by manual control of the speed of the train. (49CFR236)
For-Hire Carriage	Transportation of property by motor vehicle except when 1) The property is transported by a person engaged in a business other than transportation; and 2) The transportation is within the scope of, and furthers a primary business (other than transportation) of, the person. (49CFR387)
For-Hire Motor Carrier	A person engaged in the transportation of goods or passengers for compensation. (49CFR390)
Forklift Truck	A high-powered vehicle equipped with hydraulic driven protruding metal blades, that is used to raise and lower unitized freight. (MARAD1)
Form 41 Filer	Any primarily passenger airline carrier that files a "Form 41" with the Department of Transportation. These carriers are not required to file in the 1992 Economic Census. (BOC2)
Formation Flight	(See also Altitude Reservation) More than one aircraft which, by prior arrangement between the pilots, operate as a single aircraft with regard to navigation and position reporting. Separation between aircraft within the formation is the responsibility of the flight leader and the pilots of the other aircraft in the flight. This includes transition periods when aircraft within the formation are maneuvering to attain separation from each other to effect individual control and during join-up and breakaway. 1) A standard formation is one in which a proximity of no more than 1 mile laterally or longitudinally and within 100 feet vertically from the flight leader is maintained by each wingman. 2) Nonstandard formations are those operating under any of the following conditions a) When the flight leader has requested and Air Traffic Control (ATC) has approved other than standard formation dimensions. b) When operating within an authorized altitude reservation (ALTRV) or under the provisions of a letter of agreement. c) When the operations are conducted in airspace specifically designed for a special activity. (FAA4)
Formula Capital Grants	Federal transit funds for transit operators; allocation of funds overseen by FTA.
Forward Control	A configuration in which more than half of the engine length is rearward of the foremost point of the windshield base and the steering wheel hub is in the forward quarter of the vehicle length. (49CFR571)
Forward Wing	A forward lifting surface of a canard configuration or tandem-wing configuration airplane. The surface may be a fixed, movable, or variable geometric surface, with or without control surfaces. (14CFR1)
Fossil Fuel	Any naturally occurring organic fuel, such as petroleum, coal, and natural gas. (DOE3)
Fossil Fuels	Any naturally occurring organic fuel formed in the Earth’s crust, such as petroleum, coal, and natural gas.
Foul Bill of Lading	A receipt for goods issued by a carrier with an indication that the goods were damaged when received. (USTTA1)
Foul Ground	An area identified as a danger to maritime navigation where the holding qualities for an anchor are poor, or where danger exists of striking or fouling the ground or other obstructions. (DOI3)
Fouling Section	The section of track between the switch points and the clearance point in a turnout. (49CFR236)
Four Banger	Four cylinder engine. (ATA1)
Four By Four	Four speed transmission and 4 speed auxiliary transmission. (ATA1)
Frangible Navigational Aid (NAVAID)	A navigational aid whose properties allow it to fail at a specified impact load. (FAA12)
Free Alongside Ship (FAS)	A price quotation under which the exporter quotes a price that includes delivery of the goods to the vessel's side and within reach of its loading tackle. Subsequent risks and expenses are for the account of the buyer. (TNDOT1)
Free Alongside Ship Value (FAS)	The value of a commodity at the port of exportation, generally including the purchase price plus all charges incurred in placing the commodity alongside the carrier at the port of exportation in the country of exportation. (DOE5)
Free In	A pricing term indicating that the charterer of a vessel is responsible for the cost of loading goods onto the vessel. (USTTA1)
Free In and Out	Terms under which cost of loading and discharging cargo is borne by parties other than vessel owner or operator. (TNDOT1)
Free of Particular Average	A marine insurance term meaning that assurer will not allow payment for partial loss or damage to a foreign shipment. (TNDOT1)
Free On Board (FOB)	1) A price quotation under which the exporter quotes a price that includes delivery of the goods on board the vessel. Subsequent risks and expenses are for the account of the buyer. 2) A transaction whereby the seller makes the product available within an agreed-on period at a given port at a given price. It is the responsibility of the buyer to arrange for the transportation and insurance. (DOE3) (DOE5) (TNDOT1) (USTTA1)
Free On Board (FOB) Airport	FOB airport is based on the same principle as the ordinary FOB term. The seller's obligation include delivering the goods to the air carrier at the airport of departure. The risk of loss or damage to the goods is transferred from the seller to the buyer when the goods have been so delivered. (USTTA1)
Free Out (FO)	Terms under which owner of goods is responsible for discharging costs. (TNDOT1)
Free Port	A restricted area at a seaport for the handling of duty-exempted import goods. (MARAD2)
Free Time	The amount of time that a carrier's equipment may be used without incurring additional charges. (MARAD2)
Free Trade Zone	A port designated by the government of a country for duty-free entry of any non-prohibited goods. Merchandise may be stored, displayed, used for manufacturing, etc., within the zone and re-exported without duties. (MARAD2)
Freedom of Information Act (FOIA)	Allows all U.S. citizens and residents to request any records in possession of the executive branch of the federal government. The term "records" includes documents, papers, reports, letters, films, photographs, sound recordings, computer tapes and disks
Freeway	A divided arterial highway designed for the unimpeded flow of large traffic volumes. Access to a freeway is rigorously controlled and intersection grade separations are required.
Freeways and Expressways	(See also Expressway, Highway, Interstate Highway (Freeway or Expressway)) All urban principal arterial with limited control of access not on the interstate system. (NHTSA3)
Freeze Calculated Landing Time (FCLT)	A dynamic parameter number of minutes prior to the meter fix calculated time of arrival for each aircraft when the Tentative Calculated Landing Time (TCLT) is frozen and becomes an Actual Calculated Landing Time (ACLT) (i.e., the Vertex Time of Arrival (VTA) is updated and consequently the TCLT is modified as appropriate until Freeze Calculated Landing Time (FCLT) minutes prior to meter fix calculated time of arrival, at which time updating is suspended and an ACLT and a frozen meter fix crossing time (MFT) is assigned). (FAA4)
Freeze/Frozen	Terms used in referring to arrivals which have been assigned Actual Calculated Landing Times (ACLTs) and to the lists in which they are displayed. (FAA4)
Freight	Any commodity being transported. (ATA2)
Freight Agent	An establishment that arranges the transportation of freight and cargo for a fee. Revenue for freight agents (also known as shipping agents or brokers) represents commissions of fees and not the gross charges for transporting goods. (BOC2)
Freight All Kinds (FAK)	Goods classified FAK are usually charged higher rates than those marked with a specific classification and are frequently in a container that includes various classes of cargo.
Freight All Kinds (FAK)	Goods classified FAK are usually charged higher rates than those marked with a specific classification and are frequently in a container which includes various classes of cargo. (USTTA1)
Freight and Other Transportation Services Forwarding	Includes establishments that provide forwarding, packing, and other services incidental to transportation. Also included are horse-drawn cabs and carriages for-hire. (BEA1)
Freight Broker	A person whose business it is to prepare shipping and customs documents for international shipments. Brokers often have offices at major freight gateways, including border crossings, seaports, and airports.
Freight Container	A reusable container having a volume of 64 cubic feet or more, designed and constructed to permit being lifted with its contents intact and intended primarily for containment of packages (in unit form) during transportation. (49CFR171)
Freight Forwarder	A person whose business is to act as an agent on behalf of a shipper. A freight forwarder frequently consolidates shipments from several shippers and coordinates booking reservations.
Freight Forwarding	Establishments primarily engaged in undertaking the transportation of goods from shippers to receivers for a charge covering the entire transportation, and in turn making use of the services of various freight carriers in effecting delivery. Establishment pays transportation charges as part of its costs of doing business and assumes responsibility for delivery of the goods. There are no direct relations between shippers and the various freight carriers performing the movement. (BOC1)
Freight Revenue	Revenues from the transportation by air of property other than passenger baggage. (BTS4)
Freight Revenue (Rail)	Revenue from the transportation of freight and from the exercise of transit, stopoff, diversion, and reconsignment privileges as provided for in tariffs.
Freight Service Operating Expenses	The sum of operating expenses directly assignable to freight service and an apportionment of expenses common to both freight and passenger service. (AAR1)
Freight Service Revenue	Revenue from the transportation of freight, switching of freight train cars, water transfers of freight, vehicles and livestock, movement of freight trains at a rate per train mile or for a lump sum, storage of freight, demurrage, grain elevators, stockyards, and miscellaneous services and facilities in connection with the transportation of freight. (AAR1)
Freighters (Water)	General cargo carriers, full containerships, partial containerships, roll-on/rolloff ships, and barge carriers.
Fringe Parking	An area for parking usually located outside the Central Business District (CBD) and most often used by suburban residents who work or shop downtown. (APTA1)
Frog	A track component used at the intersection of two running rails to provide support and guidance for the wheels. It allows wheels on each rail to cross the other rail. (TRB1)
From	A shipping term under which price quoted applies only at the point of origin, such as ex-mill, ex-rail car, ex-barge, and the seller agrees to place the goods at the disposal of the buyer at the agreed place within a fixed period of time. (TNDOT1)
From (Lower) End of Dike	From the outward or channel end of dike. (TNDOT1)
From a Little Open	An expression meaning to depart on a new course from a point 50 yards or less from a defined object. (TNDOT1)
From Foot of Dike	From the end of the dike where it is attached to the shore. (TNDOT1)
Fuel	See also Gasohol, Gasoline, Kerosene.
Fuel Cell	A device that produces electrical energy directly from the controlled electrochemical oxidation of the fuel. It does not contain an intermediate heat cycle, as do most other electrical generation techniques. (DOE5)
Fuel Code	A 2-digit numeric code that identifies the type of fuel used. The code identifies regular (gasoline and diesel) fuels, alternative fuels such as natural gas and methanol, and vehicles able to operate on a combination of these fuels (regular and alternative). (GSA2)
Fuel Dumping	(See also Jettisoning of External Stores) Airborne release of usable fuel. This does not include the dropping of fuel tanks. (FAA4)
Fuel Fire/Explosion	Accidental combustion of vessel fuel, liquids, including their vapors, or other substance such as wood or coal. (USCG2)
Fuel Injection	(See also Carburetor, Diesel Fuel System) A fuel delivery system whereby gasoline is pumped to one or more fuel injectors under high pressure. The fuel injectors are valves that, at the appropriate times, open to allow fuel to be sprayed or atomized into a throttle bore or into the intake manifold ports. The fuel injectors are usually solenoid operated valves under the control of the vehicle's on-board computer (thus the term "electronic fuel injection"). The fuel efficiency of fuel injection systems is less temperature dependent than carburetor systems. Diesel engines always use injectors. (DOE4)
Fuel Oil	A liquid petroleum product less volatile than gasoline, used as an energy source. Fuel oil includes distillate fuel oil (No. 1, No. 2, and No. 4), residual fuel oil (No. 5 and No. 6), and kerosene. (DOE5)
Fuel Oil, No. 1	A light distillate fuel oil intended for use in vaporizing pot-type burners. ASTM Specification D 396 specifies for this grade maximum distillation temperatures of 400 degrees Fahrenheit at the 10-percent point and 550 degrees Fahrenheit at the 90-percent point, and kinematic viscosities between 1.4 and 2.2 centistokes at 100 degrees Fahrenheit. (DOE2)
Fuel Oil, No. 2	A distillate fuel oil for use in atomizing type burners for domestic heating or for moderate capacity commercial-industrial burner units. ASTM Specification D 396 specifies for this grade distillation temperatures at the 90-percent point between 540 and 640 degrees Fahrenheit, and kinematic viscosities between 2.0 and 3.6 centistokes at 100 degrees Fahrenheit. (DOE2)
Fuel Oil, No. 4	A fuel oil for commercial burner installations not equipped for preheating facilities. It is used extensively in industrial plants. This grade is a blend of distillate fuel oil and residual fuel oil stocks that conform to ASTM Specification D 396 or Federal Specification VV-F-815C; its kinematic viscosity is between 5.8 and 26.4 centistokes at 100 degrees Fahrenheit. Also included is No. 4-D, a fuel oil for lower and medium-speed diesel engines that conforms to ASTM Specification D 975. (DOE2)
Fuel Remaining	(See also Minimum Fuel) A phrase used by either pilots or controllers when relating to the fuel remaining on board until actual fuel exhaustion. When transmitting such information in response to either a controller question or pilot initiated cautionary advisory to air traffic control, pilots will state the appropriate number of minutes the flight can continue with the fuel remaining. All reserve fuel should be included in the time stated, as should an allowance for established fuel gauge system error. (FAA4)
Fuel Siphoning	Unintentional release of fuel caused by overflow, puncture, loose cap, etc. (FAA4)
Fuel Tank	A tank other than a cargo tank, used to transport flammable or combustible liquid, or compressed gas for the purpose of supplying fuel for propulsion of the transport vehicle to which it is attached, or for the operation of other equipment on the transport vehicle. (49CFR171)
Fuel Tank Fitting	Any removable device affixed to an opening in the fuel tank with the exception of the filler cap. (49CFR393)
Fuel Taxed Waterway System	Eleven thousand miles of the U.S. Waterway system designated by the Water Resources Development Act of 1986. Commercial users of this system pay a per gallon fuel tax which is deposited in the Inland Waterways Trust Fund and used to fund inland navigation projects each year.
Fueling	Any stage of the fueling operation; primarily concerned with introduction of explosive or combustible vapors or liquids on board. (USCG2)
Full Berth Terms (FBT) (FBT)	Terms under which cost of loading and discharge is included in the steamship rate quoted. Ship owner pays loading and discharge costs. (TNDOT1)
Full Double	The maximum tow that can be locked. (TNDOT1)
Full Trailer	A truck-trailer with front and rear axles. The load weight is distributed over both the front axle(s) and rear axle(s). (BOC3)
Fullmount	A smaller vehicle mounted completely on the frame of either the first or last vehicle in a saddlemount combination. (23CFR658)
Furniture Van Body	Truck body designed for the transportation of household goods; usually a van of drop-frame construction. (ATA1)
Further Clearance Time	The time a pilot can expect to receive clearance beyond a clearance limit. (FAA4)
Future Needs	Represents the gap between the vision and the current or porjected performance of the system
Gage	A scale graduated in tenths of a foot which indicates the water level or river stage. (TNDOT1)
Gaging Station	A structure used to measure the characteristics of a hydrographic feature. (DOI3)
Gallon	(See also Barrel) A volumetric measure equal to 4 quarts (231 cubic inches) used to measure fuel oil. One barrel equals 42 gallons. (DOE5)
Gantry	A frame structure raised on side supports so as to span over or around something. (DOI4)
Gantry Crane	A crane hoisting machine mounted on a frame or structure spanning an intervening space. Used primarily in modern container handling ports. (TNDOT1)
Gap	Low point or opening between hills or mountains or in a ridge or mountain range. (DOI4)
Garage	A space large enough to accommodate a car, with a door opening at least six feet wide and seven feet high. "Attached" means it is under part or all of the house or it shares part of a wall in common with the house. Not included are carports, barns, or buildings (not connected to the house) or storage space for golf carts or motorcycles. (DOE5)
Garbage and Trash Collection	Establishments primarily engaged in collecting and transporting garbage, trash, and refuse, within a city, town, or other local area, including adjoining towns and suburban areas. (BOC1)
Gas	(Except when designated as inert) Natural gas, other flammable gas, or gas which is toxic or corrosive. (49CFR193)
Gas Distribution Company	Company which obtains the major portion of its gas operating revenues from the operation of a retail gas distribution system, and which operates no transmission system other than incidental connections within its own system or to the system of another company. (AGA1)
Gas Guzzler Tax	Originates from the 1978 Energy Tax Act (Public Law 95418). A new car purchaser is required to pay the tax if the car purchased has a combined city/highway fuel economy rating that is below the standard for that year. For model years 1986 and later, the standard is 22.5 mpg. (DOE6)
Gas Transmission Pipelines	Pipelines installed for the purpose of transmitting gas from a source or sources of supply to one or more distribution centers, or to one or more large volume customers; or a pipeline installed to interconnect sources of supply. Typically, transmission lines differ from gas mains in that they operate at higher pressures and the distance between connections is greater.
Gasohol	A blend of finished motor gasoline (leaded or unleaded) and alcohol (generally ethanol but sometimes methanol) limited to 10 percent by volume of alcohol.
Gasoline	A complex mixture of relatively volatile hydrocarbons, with or without small quantities of additives that have been blended to produce a fuel suitable for use in spark ignition engines. Motor gasoline includes both leaded or unleaded grades of finished motor gasoline, blending components, and gasohol. Leaded gasoline is no longer used in highway motor vehicles in the United States.
Gasoline Aviation/Gasoline Blending Components	Naphthas that will be used for blending or compounding into finished aviation gasoline (e.g., straight-run gasoline, alkylate, reformate, benzene, toluene, and xylene). Excludes oxygenates (alcohols, ethers), butane, and pentanes plus. Oxygenates are reported as other hydrocarbons, hydrogen, and oxygenates. (DOE5)
Gate	A structure that may be swung, drawn or lowered to block an entrance or passageway. (DOI3)
Gate Dam	A type of opening in a dam whereby the water passes over the top. (TNDOT1)
Gate Hold Procedure	Procedures at selected airports to hold aircraft at the gate or other ground location whenever departure delays exceed or are anticipated to exceed 16 minutes. The sequence for departure will be maintained in accordance with initial call-up unless modified by flow control restrictions. Pilots should monitor the ground control and clearance delivery frequency for engine start/taxi advisories or new proposed start/taxi time if the delay changes. (FAA4)
Gateway	In the context of travel activities, gateway refers to a major airport or seaport. Internationally, gateway can also mean the port where customs clearance takes place. (USTTA1)
Gathering Line	A pipeline 219.1 mm (8 5/8 inches) or less nominal diameter that transports petroleum from a production facility. (49CFR195)
Gauge	See also Gage.
Gear Bonger	Driver who grinds gears when shifting. (ATA1)
Gear Jammer	One who constantly clashes the gears. (ATA1)
Gear Ratio	The number of revolutions a driving gear requires to turn a driven gear one revolution. For a pair of gears, the ratio is found by dividing the number of teeth on the driven gear by the number of teeth on the driving gear. (GSA2)
General Accounting Office (GAO)	The General Accounting Office is the audit, evaluation, and investigative arm of Congress. GAO exists to support the Congress in meeting its Constitutional responsibilities and to help improve the performance and ensure the accountability of the federal government for the American people. GAO examines the use of public funds, evaluates federal programs and activities, and provides analyses, options, recommendations, and other assistance to help the Congress make effective oversight, policy, and funding decisions. In this context, GAO works to continuously improve the economy, efficiency, and effectiveness of the federal government through financial audits, program reviews and evaluations, analyses, legal opinions, investigations, and other services. GAO's activities are designed to ensure the executive branch's accountability to the Congress under the Constitution and the government's accountability to the American people. GAO is dedicated to good government through its commitment to the core values of accountability, integrity, and reliability.
General Administration	All activities associated with the general administration of the transit system, including transit system development, injuries and damages, safety, personnel administration, legal services, insurance, data processing, finance and accounting, purchasing and stores, engineering, real estate management, office management and services, customer services, promotion, market research and planning. (FTA1)
General and Administrative Expenses	Expenses of a general corporate nature and expenses incurred in performing activities which contribute to more than a single operating function such as general financial accounting activities, purchasing activities, representation at law, and other general operational administration not directly applicable to a particular function. Passenger service, aircraft and traffic servicing, and promotion and sales expenses are also included for certain small air carriers. (BTS4)
General Average	A general loss voluntarily incurred to save all interest involved in a common maritime adventure from an impending peril including hull, cargo, and freight at risk. (TNDOT1)
General Aviation	1) All civil aviation operations other than scheduled air services and nonscheduled air transport operations for taxis, commuter air carriers, and air travel clubs that do not hold Certificates of Public Convenience and Necessity. 2) All civil aviation activity except that of air carriers certificated in accordance with Federal Aviation Regulations, Parts 121, 123, 127, and 135. The types of aircraft used in general aviation range from corporate multiengine jet aircraft piloted by professional crews to amateur-built single-engine piston-driven acrobatic planes to balloons and dirigibles.
General Aviation Airport	Any airport which is used or to be used for public purposes, under the control of a public agency, the landing area of which is publicly owned. (FAA2)
General Aviation District Office (GADO) (GADO)	A Federal Aviation Administration (FAA) field office serving a designated geographical area and staffed with Flight Standards personnel who have the responsibility for serving the aviation industry and the general public on all matters relating to the certification and operation of general aviation aircraft. (FAA4)
General Aviation Operations	Takeoffs and landings of all civil aircraft, except those classified as air carriers or air taxis. (FAA13) (FAA14)
General Cargo	General cargo consists of those products or commodities such as timber, structural steel, rolled newsprint, concrete forms, agricultural equipment that are not conducive to packaging or unitization. Break-bulk cargo (e.g., packaged products such as lubricants and cereal) are often regarded as a subdivision of general cargo. (MARAD1)
General Cargo Ship	(See also Boat, Motorboat) A ship configured to accommodate general, break-bulk, and containerized cargoes. Cargo handling operations are labor intensive and conducted with either ship's cranes or jib cranes onshore. These ships traditionally have numerous holds located on several decks, have smaller hatches than bulk carriers or containerships, and are usually equipped with a boom or crane positioned at each hatch cover. (MARAD1)
General Estimates System (Highway)	A data-collection system that uses a nationally representative probability sample selected from all police-reported highway crashes. It began operation in 1988.
General Export License	Authorization to export without specific documentary approval. (TNDOT1)
General Freight Carrier	A carrier which handles a wide variety of commodities. (ATA2)
General Utility, Stage I Airport	This type of airport serves all small airplanes. Precision approach operations are not usually anticipated. This airport is designed for airplanes in Airport Reference Code B-II. (FAA12)
General Utility, Stage II Airport	This type of airport serves large airplanes in Aircraft Approach Category A and B and usually has the capability for precision approach operations. This airport is normally designed for Airport Reference Code B-III. (FAA12)
General Warehousing and Storage	Establishments primarily engaged in the warehousing and storage of a general line of goods. (BOC1)
Geo Map	The digitized map markings associated with the Airport Surveillance Radar (ASR-9) Radar System. (FAA4)
Geographic Information System (GIS)	1) Computerized data management system designed to capture, store, retrieve, analyze, and display geographically referenced information. 2) A system of hardware, software, and data for collecting, storing, analyzing, and disseminating information about areas of the Earth. For Highway Performance Monitoring System (HPMS) purposes, Geographical Information System (GIS) is defined as a highway network (spatial data which graphically represents the geometry of the highways, an electronic map) and its geographically referenced component attributes (HPMS section data, bridge data, and other data including socioeconomic data) that are integrated through GIS technology to perform analyses. From this, GIS can display attributes and analyze results electronically in map form. (FHWA2)
Gigawatt (GW) (GW)	(See also Electricity, Kilowatt, Megawatt) One billion watts or one thousand megawatts. (DOE5)
Gigawatt Electric (GWE) (GWE)	One billion watts of electric capacity. (DOE5)
Gigawatt Hour (GWH) (GWH)	One billion watthours. (DOE5)
Glad Hands	Air hose brake system connections between tractor and trailer. (ATA1)
Glidepath	A descent profile determined for vertical guidance during a final approach. (FAA4)
Glider	A heavier-than-air aircraft, that is supported in flight by the dynamic reaction of the air against its lifting surfaces and whose free flight does not depend principally on an engine. (14CFR1)
Glideslope	(See also Instrument Landing System, Intercept Glideslope Altitude, Localizer, Middle Marker, Outer Marker) Provides vertical guidance for aircraft during approach and landing. The glideslope/glidepath is based on the following 1) Electronic components emitting signals which provide vertical guidance by reference to airborne instruments during instrument approaches such as Instrument Landing System (ILS)/Microwave Landing System (MLS), or 2) Visual ground aids, such as Visual Approach Slope Indicator (VASI), which provide vertical guidance for a Visual Flight Rules (VFR) approach or for the visual portion of an instrument approach and landing or 3) Used by Air Traffic Control (ATC) to inform an aircraft making a Precision Approach Radar (PAR) approach of its vertical position (elevation) relative to the descent profile. (FAA4)
Global Positioning System (GPS)	A space base radio positioning, navigation, and time transfer system being developed by the Department of Defense. When fully deployed, the system is intended to provide highly accurate position and velocity information, and precise time, on a continuous
Go Ahead	Proceed with your message. Not to be used for any other purpose. (FAA4)
Go Around	(See also Missed Approach) Instructions for a pilot to abandon his approach to landing. Additional instructions may follow. Unless otherwise advised by Air Traffic Control (ATC), a Visual Flight Rules (VFR) aircraft or an aircraft conducting visual approach should overfly the runway while climbing to traffic pattern altitude and enter the traffic pattern via the crosswind leg. A pilot on an Instrument Flight Rules (IFR) flight plan making an instrument approach should execute the published missed approach procedure or proceed as instructed by ATC. (FAA4)
Go Well Over	A term applied in making a crossing meaning to go well over near the shore on the opposite side before turning out to either shape the shore or pass an easy distance off before coming up on the next set of marks. (TNDOT1)
Goals	Generalized statements which broadly relate to the physical environment to values
Goat 'N' Shoat Man	Driver of a livestock carrier. (ATA1)
Good Condition Classification	No corrective maintenance is needed at time of inspection. Facility is serving the purpose for which it was constructed. (DOI2)
Goods	See also Cargo, Commodity, Freight, Product.
Government Aid Cargo	The tonnes of cargo assessed at the Government aid rate of tolls as defined in the St. Lawrence Seaway Tariff of Tolls. (SLSDC1)
Government Fleet Vehicle	Includes vehicles owned by all federal General Services Administration (GSA), state, county, city, and metro units of government, including toll road operations. (DOE6)
Government Leased Vehicle	A vehicle obtained by an executive agency by contract or other source for a period of 60 continuous days or more. (GSA2)
Government Light	A colloquial term applied to an aid to navigation maintained by the Coast Guard. (TNDOT1)
Government Owned Contractor Operated Vehicle	A vehicle that is owned or leased by the Federal Government but used by a contractor under a cost reimbursement contract with a Federal agency. (GSA2)
Government Owned Vehicle	A vehicle that is owned by the Federal Government. (GSA2)
Government Transportation Expenditures	Expenditures are the final actual costs for capital goods and operating services covered by the government transportation program. (BTS3)
Government Transportation Revenue	The transportation revenue estimates contained in this report consist of those funds identified as government transportation-related user charges, taxes or fees in the various data sources. Therefore, general revenue is not included. (BTS3)
Governor	A device which limits the speed of an engine. A governor is also a part on an automatic transmission which signals internal transmission components to shift to a higher gear. (GSA2)
Grab One	To shift into a lower gear as a means of gaining power when driving uphill. (ATA1)
Gradability	The ability of a vehicle to negotiate a given grade at a specified Gross Combination Weight Rating (GCWR) or Gross Vehicle Weight Rating (GVWR). It is the measure of the starting and grade climbing ability of a vehicle, and is expressed in percent grade, (1 percent is a rise of 1 foot in a horizontal distance of 100 feet). (GSA2)
Grade Crossings	(See also At Grade, Highway-Rail Crossing, Rail-Highway Grade Crossing) An intersection of highway roads, railroad tracks, or dedicated transit rail tracks that run either parallel or across mixed traffic situations with motor vehicles, light rail, commuter rail, heavy rail, trolleybus or pedestrian traffic. Collisions at grade crossings involving transit vehicles apply only to light rail, commuter rail, heavy rail or trolleybus. (FTA1)
Gradually Pull Down	To swing slowly to a new course on a mark further downstream. (TNDOT1)
Gradually Pull Down Shape of Bend	Term used in crossings meaning to keep well out until tow is well down, then alter course to follow the shore shape of the bend. (TNDOT1)
Gradually Pull Down Shore	Term used in crossings meaning, when well over, to gradually swing the vessel's head downstream along the shore. (TNDOT1)
Grain Body	Low side, open top truck body designed to transport dry fluid commodities. (ATA1)
Grain Cargo	The tonnes of cargo assessed at the Food or Feed Grains rate of tolls as defined in the St. Lawrence Seaway Tariff of Tolls. (SLSDC1)
Grandma	See Creeper Gear.
Grants	A federal financial assistance award making payment in cash or in kind for a specified purpose. The federal government is not expected to have substantial involvement with the state or local government or other recipient while the contemplated activity is being performed. The term "grants-in-aid" is commonly restricted to grants to states and local governments. (BTS3)
Great Lakes-St. Lawrence Seaway Freight Transportation	Establishments primarily engaged in the transportation of freight on the Great Lakes and St. Lawrence Seaway, either between U.S. ports or between U.S. and Canadian ports. (BOC1)
Great River Environmental Action Team	A multi-agency planning group organized to develop a resource management plan for the Upper Mississippi River. Operates under the auspices of the Upper Mississippi River Basin Commission. (TNDOT1)
Gross Axle Weight Rating (GAWR) (GAWR)	The value specified by the vehicle manufacturer as the load carrying capacity of a single axle system, as measured at the tire-ground interfaces. (49CFR571)
Gross Combination Weight (GCW) (GCW)	The maximum allowable fully laden weight of a tractor and its trailer(s). (ATA2)
Gross Combination Weight Rating (GCWR) (GCWR)	The value specified by the manufacturer as the loaded weight of a combination (articulated) vehicle. In the absence of a value specified by the manufacturer, GCWR will be determined by adding the Gross Vehicle Weight Rating (GVWR) of the power unit and the total weight of the towed unit and any load thereon. (49CFR383) (49CFR390) (49CFR571) (GSA2)
Gross Domestic Product (GDP)	1) The total value of goods and services produced by labor and property located in the United States. As long as the labor and property are located in the United States, the supplier (that is, the workers and, for property, the owners) may be either U.S. residents or residents of foreign countries. (DOE3) 2) The total output of goods and services produced by labor and property located in the United States, valued at market prices. As long as the labor and property are located in the United States, the suppliers (workers and owners) may be either U.S. residents or residents of foreign countries.
Gross Head	A dam's maximum allowed vertical distance between the upstream's surface water (headwater) forebay elevation and the downstream's surface water (tailwater) elevation at the tail-race for reaction wheel dams or the elevation of the jet at impulse wheel dams during specified operation and water conditions. (DOE5)
Gross Horsepower	The power of a basis engine at a specified revolution per mile (RPM) without alternator, water pumps, fan, etc. Gross horsepower is the figure commonly given as the horsepower rating of an engine. (GSA2)
Gross National Product (GNP)	A measure of monetary value of the goods and services becoming available to the nation from economic activity. Total value at market prices of all goods and services produced by the nation's economy. Calculated quarterly by the Department of Commerce, the Gross National Product is the broadest available measure of the level of economic activity. (DOE6)
Gross Registered Tonnage (GR) (GR)	The capacity of a vessel in cubic feet of the spaces within the hull and of the enclosed spaces above the main deck available for cargo, stores, and crew, divided by 100. (TNDOT1)
Gross Registered Tonnage (GRT) (GRT)	The gross registered tonnage of a vessel according to the country of registry. (SLSDC1)
Gross Ton Mile	The number of tons behind the locomotive (cars and contents, company service equipment, and cabooses) times the distance moved in road freight trains. (AAR1)
Gross Tonnage	The gross tonnage of a vessel is the internal cubic capacity of all spaces in and on the vessel which is permanently enclosed, with the exception of certain permissible exemptions. It is expressed in tons of 100 cubic feet. (USCG4)
Gross Vehicle Weight (GVW)	The combined total weight of a vehicle and its freight.
Gross Vehicle Weight (GVW) (GVW)	The maximum allowable weight in pounds or tons that a truck is designed to carry. (ATA2)
Gross Vehicle Weight Rating (GVWR) (GVWR)	The maximum loaded weight in pounds of a single vehicle. Vehicle manufacturers specify the maximum Gross Vehicle Weight Rating (GVWR) on the vehicle certification label. (49CFR383) (49CFR390) (49CFR571) (GSA2)
Gross Vehicle Weight Rating (Truck)	The maximum rated capacity of a vehicle, including the weight of the base vehicle, all added equipment, driver and passengers, and all cargo.
Gross Weight	Entire weight of goods, packing, and container, ready for shipment.
Gross Weight/Mass	The weight of a packaging plus the weight of its contents. (49CFR171)
Ground	The flat horizontal surface on which the tires of a motor vehicle rest. (49CFR399)
Ground Controlled Approach (GCA) (GCA)	(See also Airport Surveillance Radar, Precision Approach Radar) A radar approach system operated from the ground by air traffic control personnel transmitting instructions to the pilot by radio. The approach may be conducted with airport surveillance radar (ASR) only or with both surveillance and precision approach radar (PAR). Usage of the term "GCA" by pilots is discouraged except when referring to a Ground Controlled Approach (GCA) facility. Pilots should specifically request a "PAR" approach when a precision radar approach is desired or request an "ASR" or "surveillance" approach when a nonprecision radar approach is desired. (FAA4)
Ground Delay	The amount of delay attributed to Air Traffic Control (ATC), encountered prior to departure, usually associated with a Controlled Departure Time (CDT) program. (FAA4)
Ground Property, Equipment and Other	The total cost of ground property and equipment and land. (BTS4)
Ground Speed	The speed of an aircraft relative to the surface of the earth. (FAA4)
Ground Stop	Normally, the last initiative to be utilized; this method mandates that the terminal facility will not allow any departures to enter the Air Route Traffic Control Center (ARTCC) airspace until further notified. (FAA4)
Ground Surface	The land surface of the earth, both exposed and underwater. (DOI4)
Ground Visibility	Prevailing horizontal visibility near the earth's surface as reported by the United States National Weather Service or an accredited observer. (14CFR1)
Grounding	Running aground of a vessel, striking or pounding on rocks, reefs, or shoals; stranding. (USCG2)
Group II Railroad	Railroads, excluding Class I, with an annual accumulation of over 400,000 employee hours worked. (FRA3)
Guaranteed Funding	Highway, highway safety, and transit spending protected by firewalls, plus highway funds that are classified as mandatory spending, i.e., exempt from the obligation limitation.
Guard Rail	A strong fence or barrier to prevent vehicles from leaving the roadway, or for people's safety. (DOI4)
Guard Wall	The river wall of a lock which prevents boats from being drawn into the dam. (TNDOT1)
Guide Wall	(See also Lead Wall) The extension of the inner lock wall on the upper and lower side of the lock chamber to assist navigators in guiding vessels or tows into the lock chamber. It is usually 600 feet in length, although some are now 1,200 feet long. (TNDOT1)
Guideway	In transit systems, a track or other riding surface (including supporting structure) that supports and physically guides transit vehicles specifically designed to travel exclusively on it. (TRB1)
Gulf of Mexico and Its Inlets	The waters from the mean high water mark of the coast of the Gulf of Mexico and its inlets open to the sea (excluding rivers, tidal marshes, lakes, and canals) seaward to include the territorial sea and Outer Continental Shelf (OCS) to a depth of 15 feet, as measured from the mean low water. (49CFR195)
Gum Ball Machine	Rotating warning light on top of an emergency vehicle. (ATA1)
Gypsy	1) An independent truck operator who drives his own truck and secures freight wherever he can. 2) One who trip leases to authorized carriers. (ATA1)
Gyrodyne	A rotorcraft whose rotors are normally engine driven for takeoff, hovering, and landing, and for forward flight through part of its speed range, and whose means of propulsion, consisting usually of conventional propellers, is independent of the rotor system. (14CFR1)
Gyroplane	(See also Helicopter) A rotorcraft whose rotors are not engine driven, except for initial starting, but are made to rotate by action of the air when the rotorcraft is moving; and whose means of propulsion, consisting usually of conventional propellers, is independent of the rotor system. (14CFR1)
H Point	The mechanically hinged hip point of a manikin which simulates the actual pivot center of the human torso and thigh, described in Society of Automotive Engineers (SAE) Recommended Practice J826, "Manikins for Use in Defining Vehicle Seating Accommodations," November 1962. (49CFR571)
Hand Operated Switch	A non-interlocked switch which can only be operated manually. (49CFR236)
Handling	Physically moving cargo between point-of-rest and any place on the terminal facility, other than the end of ship's tackle. (MARAD1)
Handoff	A Controller action taken to transfer the radar identification of an aircraft from one Controller to another if the aircraft will enter the receiving Controller's airspace and radio communications with the aircraft will be transferred. (FAA4) (FAA8)
Handy Line	Small line used to throw between separated barges or boat and shore, (i.e., heaving line). (TNDOT1)
Harbor	An area of water where ships, planes, or other watercraft can anchor or dock. (DOI4)
Harbor Line	See Permit Line.
Harbor Master	An officer who attends to the berthing, etc., of ships in a harbor. (MARAD2)
Harmonized System of Codes	An international goods classification system for describing cargo in international trade under a single commodity coding scheme. This code is a hierarchically structured product nomenclature containing approximately 5,000 headings and subheadings. (MARAD2)
Haulage Cost	Cost of loading ore at a mine site and transporting it to a processing plant. (DOE5)
Hauling Post Holes	Driving an empty truck or trailer. (ATA1)
Have Numbers	Used by pilots to inform Air Traffic Control (ATC) that they have received runway, wind, and altimeter information only. (FAA4)
Hawser	A tow line. (TNDOT1)
Hazard to Navigation	For the purpose of 49CFR195, a pipeline where the top of the pipe is less than 12 inches below the seabed in water less than 15 feet deep, as measured from the mean low water. (49CFR195)
Hazard Warning Signal	Lamps that flash simultaneously to the front and rear, on both the right and left sides of a commercial motor vehicle, to indicate to an approaching driver the presence of a vehicular hazard. (49CFR393)
Hazard Zone	An area identified as a danger to maritime navigation. (DOI3)
Hazardous Area Reporting Service	Flight monitoring for Visual Flight Rules (VFR) aircraft crossing large bodies of water, swamps, and mountains. This service is provided for the purpose of expeditiously alerting Search and Rescue (SAR) facilities when required. Radio contacts are desired at least every 10 minutes. If contact is lost for more than 15 minutes, SAR will be alerted. (FAA8)
Hazardous Goods	The categories of hazardous goods carried by inland waterways are those defined by the European Provisions concerning the International Carriage of Dangerous Goods by Inland Waterways. (TNDOT1)
Hazardous Inflight Weather Advisory Service (HIWAS)	Continuous recorded hazardous inflight weather forecasts broadcasted to airborne pilots over selected very high frequency omnidirectional (VOR) outlets defined as an HIWAS BROADCAST AREA. (FAA4)
Hazardous Liquid	Liquefied Natural Gas (LNG) or a liquid that is flammable or toxic. (49CFR193)
Hazardous Material	Any toxic substance or explosive, corrosive, combustible, poisonous, or radioactive material that poses a risk to the public’s health, safety, or property, particularly when transported in commerce.
Hazardous Material (HAZMAT)	(See also Highly Volatile Liquid, Marine Pollutant) A substance or material which has been determined by the Secretary of Transportation to be capable of posing an unreasonable risk to health, safety, and property when transported in commerce, and which has been so designated. The term includes hazardous substances, hazardous wastes, marine pollutants, and elevated temperature materials as defined in this section, materials designated as hazardous under the provisions of 49 CFR 172.101 and 172.102, and materials that meet the defining criteria for hazard classes and divisions in 49 CFR 173. (49CFR171) (49CFR390)
Hazardous Material (HAZMAT) Employee	A person who is employed by a HAZMAT employer and who in the course of employment directly affects hazardous materials transportation safety. This term includes an owner-operator of a motor vehicle which transports hazardous materials in commerce. This term includes an individual, including a self-employed individual, employed by a HAZMAT employer who, during the course of employment 1) Loads, unloads, or handles hazardous materials; 2) Tests, reconditions, repairs, modifies, marks, or otherwise represents containers, drums, or packagings as qualified for use in the transportation of hazardous materials; 3) Prepares hazardous materials for transportation; 4) Is responsible for safety of transporting hazardous materials; or 5) Operates a vehicle used to transport hazardous materials. (49CFR171)
Hazardous Material (HAZMAT) Employer	A person who uses one or more of its employees in connection with transporting hazardous materials in commerce; causing hazardous materials to be transported or shipped in commerce; or representing, marking, certifying, selling, offering, reconditioning, testing, repairing, or modifying containers, drums, or packagings as qualified for use in the transportation of hazardous materials. This term includes an owner-operator of a motor vehicle which transports hazardous materials in commerce. This term also includes any department, agency, or instrumentality of the United States, a State, a political subdivision of a State, or an Indian tribe engaged in an activity described in the first sentence of this definition. (49CFR171)
Hazardous Material Residue	The hazardous material remaining in a packaging, including a tank car, after its contents have been unloaded to the maximum extent practicable and before the packaging is either refilled or cleaned of hazardous material and purged to remove any hazardous vapors. (FRA2)
Hazardous Materials	Any toxic substance, explosive, corrosive material, combustible material, poison, or radioactive material that poses a risk to the public's health, safety, or property when transported in commerce. (FRA3)
Hazardous Substance	A material, and its mixtures or solutions, that 1) Is identified in the appendix to 49 CFR 172.101; 2) Is in a quantity, in one package, which equals or exceeds the reportable quantity (RQ) listed in the Appendix A to 49 CFR 172.101; and 3) When in a mixture or solution which, for radionuclides, conforms to paragraph 6 of Appendix A, or, for other than radionuclides, is in a concentration by weight which equals or exceeds the concentration corresponding to the RQ of the material, as shown in the Table appearing in 49 CFR 171.8. This definition does not apply to petroleum products that are lubricants or fuels. (49CFR171)
Hazardous Waste	Any material that is subject to the hazardous waste manifest requirements of the Environmental Protection Agency (EPA) specified in 40 CFR 262 or would be subject to these requirements absent an interim authorization to a State under 40 CFR 123, subpart F. (49CFR171) (49CFR390)
Head	1) The product of the water's weight and a usable difference in elevation gives a measurement of the potential energy possessed by water. 2) Marine restroom facility. (DOE5)
Head Impact Area	All nonglazed surfaces of the interior of a vehicle that are statically contactable by a 6.5-inch diameter spherical head form of a measuring device having a pivot point to "top-of-head" dimension infinitely adjustable from 29 to 33 inches in accordance with the procedure explained in 49 CFR 390.5. (49CFR571)
Head Lamps	Lamps used to provide general illumination ahead of a motor vehicle. (49CFR393)
Head Log	The heavily reinforced section at each end of the barges and at the bow of the towboat to take the pressure of pushing the entire tow. (TNDOT1)
Head of Bend	The top or upstream beginning of a bend. (TNDOT1)
Head of Navigation	The furthest (upriver) location on a river deep enough for navigation. (TNDOT1)
Head of Passes	A point near the mouth of the Mississippi River where the three principal distributary passes diverge. It is the point from which river distances are measured. (TNDOT1)
Head On Collision	1) Refers to a collision where the front end of one vehicle collides with the front-end of another vehicle while the two vehicles are traveling in opposite directions. 2) A collision in which the trains or locomotives involved are traveling in opposite directions on the same track. (FRA2) (NHTSA3)
Head On Landing	Landing in which the bow of the boat only is made fast. (TNDOT1)
Headache Rack	Heavy bulkhead that extends over cab from trailers, usually made of pipe and used in steel hauling. (ATA1)
Header Bar	Rear cross piece on open top trailer. (ATA1)
Header Board	Protective shield at front end of flat bottom trailer to prevent freight from shifting forward. (ATA1)
Headline	Mooring line used in combination to hold a fleet or barge "in". (TNDOT1)
Headwaters	The upper part of a river system, denoting the upper basin and source streams of a river. (DOI4)
Headway	The time interval between transit revenue vehicles passing a specified location. (FTA1)
Heater	Any device or assembly of devices or appliances used to heat the interior of any motor vehicle. This includes a catalytic heater which must meet the requirements of 49 CFR 177.834(1) when flammable liquid or gas is transported. (49CFR393)
Heavy Duty Truck	Truck with a gross vehicle weight generally in excess of 19,500 pounds (class 6-8). Other minimum weights are used by various law or government agencies. (ATA2)
Heavy Hauler Trailer	A trailer with one or more of the following characteristics 1) Its brake lines are designed to adapt to separation or extension of the vehicle frame; or 2) Its body consists only of a platform whose primary cargo carrying surface is not more than 40 inches above the ground in an unloaded condition, except that it may include sides that are designed to be easily removable and a permanent "front-end structure" as that term is used in 49 CFR 393.106. (49CFR393)
Heavy Lifts	Freight too heavy to be handled by regular ship's tackle. (TNDOT1)
Heavy Rail	An electric railway with the capacity for a "heavy volume" of traffic and characterized by exclusive rights-of-way, multi-car trains, high speed and rapid acceleration, sophisticated signaling, and high platform loading. (APTA1)
Heavy Rail (Rapid Rail)	Transit service using rail cars powered by electricity which is usually drawn from a third rail and usually operated on exclusive rights-of-way. It generally uses longer trains and has longer spacing between stations than light rail. (FTA2)
Heavy Rail (Transit)	An electric railway with the capacity to transport a heavy volume of passenger traffic and characterized by exclusive rights-of-way, multicar trains, high speed, rapid acceleration, sophisticated signaling, and high-platform loading. Also known as: Subway, Elevated (railway), or Metropolitan railway (metro).
Heavy Rail Passenger Cars	Rail cars with motive capability, driven by electric power taken from overhead lines or third rails, configured for passenger traffic and usually operated on exclusive right-of-way. (FTA1)
Height Above Airport	(See also Minimum Descent Altitude) The height of the Minimum Descent Altitude above the published airport elevation. This is published in conjunction with circling minimums. (FAA4)
Height Above Landing (HAL)	The height above a designated helicopter landing area used for helicopter instrument approach procedures. (FAA4)
Height Above Touchdown (HAT)	The height of the Decision Height or Minimum Descent Altitude above the highest runway elevation in the touchdown zone (first 3,000 feet of the runway). Height Above Touchdown (HAT) is published on instrument approach charts in conjunction with all straight in minimums. (FAA4)
Height/Decision Altitude	A specified altitude or height (A/H) in the precision approach at which a missed approach must be initiated if the required visual reference to continue the approach has not been established. Note 1 Decision altitude is referenced to mean sea level and decision height is referenced to the threshold elevation. Note 2 The required visual reference means that section of the visual aids or of the approach area which should have been in view for sufficient time for the pilot to have made an assessment of the aircraft position and rate of change of position, in relation to the desired flight path. (FAA4)
Helicopter	A heavier than air aircraft supported in flight chiefly by the reactions of the air on one or more power driven rotors on substantially vertical axes. (FAA4)
Helipad	A small, designated area, usually with a prepared surface, on a heliport, airport, landing/takeoff area, apron/ramp, or movement area used for takeoff, landing, or parking of helicopters. (FAA4)
Heliport	(See also Aerodrome, Aircraft Facility, Airport) 1) An area of land, water, or structure used or intended to be used for the landing and takeoff of helicopters and includes its buildings and facilities if any. 2) An area, either at ground level or elevated on a structure, that is used for the landing and take-off of helicopters and includes some or all of the various facilities useful to helicopter operations such as helicopter parking, hangar, waiting room, fueling, and maintenance equipment. (AIA1) (FAA2) (FAA4)
Helistop	A minimum facility heliport, either at ground level or elevated on a structure for the landing and takeoff of helicopters, but without such auxiliary facilities as waiting room, hangar parking, etc. (AIA1)
Here She Comes	Term used when another boat appears around a bend. (TNDOT1)
Hermetically Sealed	Closed by fusion, gasketing, crimping, or equivalent means so that no gas or vapor can enter or escape. (49CFR171)
Hertz	The standard radio equivalent of frequency in cycles per second of an electromagnetic wave. Kilohertz (kHz) is a frequency of one thousand cycles per second. Megahertz (mHz) is a frequency of one million cycles per second. (FAA4)
High Frequency	The frequency band between 3 and 30 mHz. (FAA4)
High Frequency Communications	High radio frequencies (HF) between 3 and 30 mHz used for air-to-ground voice communication in overseas operations. (FAA4)
High Occupancy Vehicle (HOV)	Vehicles carrying two or more people. The number that constitutes an HOV for the purposes of HOV highway lanes may be designated differently by different transportation agencies.
High Occupancy Vehicle Lane	Exclusive road or traffic lane limited to buses, vanpools, carpools, and emergency vehicles. (APTA1)
High Speed Rail	A rail service having the characteristics of intercity rail service which operates primarily on a dedicated guideway or track not used, for the most part, by freight, including, but not limited to, trains on welded rail, magnetically levitated (MAGLEV) vehicles on a special guideway, or other advanced technology vehicles, designed to travel at speeds in excess of those possible on other types of railroads. (49CFR37)
High Speed Taxiway	A long radius taxiway designed and provided with lighting or marking to define the path of aircraft, traveling at high speed (up to 60 knots), from the runway center to a point on the center of a taxiway. Also referred to as long radius exit or turn-off taxiway. The high speed taxiway is designed to expedite aircraft turning off the runway after landing, thus reducing runway occupancy time. (FAA4)
High Type Road Surface	High flexible, composite, rigid, etc. (Surface/Pavement Type Codes 61, 62, 71-76 and 80). (FHWA2)
High Volume Area	An area which an oil pipeline having a nominal outside diameter of 20 inches or more crosses a major river or other navigable waters, which, because of the velocity of the river flow and vessel traffic on the river, would require a more rapid response in case of a worst case discharge or substantial threat of such a discharge. (49CFR194)
High Water Buoy	Small unlighted buoy permanently secured to the end of dikes, lock walls, bear traps, and other river front structures such as mooring cells for the purpose of marking them during high water when they are submerged. (TNDOT1)
High Water Station	The location to which lights or buoys are moved when river is at or near flood stage, the purpose being 1) To guide navigation in the high water and 2) To locate the light in a position of security against loss. (TNDOT1)
Highly Volatile Liquid	(See also Hazardous Material) A hazardous liquid which will form a vapor cloud when released to the atmosphere and which has a vapor pressure exceeding 276 kPa (40 psia) at 37.8 C (100 F). (49CFR195)
High-Mileage Households	Households with estimated aggregate annual vehicle mileage that exceeds 12,500 miles. (DOE4) (DOE5)
Highway	Is any road, street, parkway, or freeway/expressway that includes rights-of-way, bridges, railroad-highway crossings, tunnels, drainage structures, signs, guardrail, and protective structures in connection with highways. The highway further includes that portion of any interstate or international bridge or tunnel and the approaches thereto (23 U.S.C. 101a). (FHWA2)
Highway Bridge Replacement and Rehabilitation Program (HBRRP)	Established under 23 U.S.C., Section 144, to enable the several states to replace and rehabilitate highway bridges when it is determined that the bridge is unsafe because of structural deficiencies, physical deterioration, or functional obsolescence.
Highway Capacity Manual	A publication of the Institute of Transportation Engineers defining level of service criteria to determine peak hour traffic congestion. (FTA1)
Highway Construction Project	A project financed in whole or in part with Federal-aid or Federal funds for the construction, reconstruction or improvement of a highway or portions thereof, including bridges and tunnels. (23CFR217)
Highway Mode	Consists of public roads and streets, automobiles, vans, trucks, motorcycles, and buses (except local transit buses) operated by transportation companies, other businesses, governments, and households, garages, truck terminals, and other facilities for motor vehicles. (BTS1) (BTS2)
Highway Performance Monitoring System (HPMS) (HPMS)	The State/Federal system used by the FHWA to provide information on the extent and physical condition of the nation's highway system, its use, performance, and needs. The system includes an inventory of the nation's highways including traffic volumes. (23CFR500)
Highway Research Information Service (HRIS) (HRIS)	A computer-based information storage and retrieval system developed by the Transportation Research Board with financial support from the state highway and transportation departments and the Federal Highway Administration. It consists of summaries of research projects in progress and abstracts of published works. (TRB1)
Highway Trust Fund (HTF)	An account established by law to hold Federal highway user taxes that are dedicated for highway and transit related purposes. The HTF has two accounts: the Highway Account, and the Mass Transit Account.
Highway User Fee or Tax	A charge levied on persons or organizations based on the use of public roads. Funds collected are usually applied toward highway construction, reconstruction and maintenance. Examples include vehicle registration fees, fuel taxes, and weight-distance taxes. (ATA2)
Highway-Rail Crossing	(See also At Grade, Grade Crossings) A location where one or more railroad tracks intersect a public or private thoroughfare, a sidewalk, or a pathway. (FRA3)
Highway-Rail Crossing Accident/Incident	An impact between on track railroad equipment and a highway user (e.g., an automobile, bus, truck, motorcycle, bicycle, farm vehicle, pedestrian or other highway user) at a designated crossing site. Sidewalks, pathways, shoulders and ditches associated with the crossing are considered to be part of the crossing site. The term "highway user" includes pedestrians, cyclists, and all other modes of surface transportation. (FRA2)
Highway-Rail Grade Crossing (Rail)	A location where one or more railroad tracks are crossed by a public highway, road, street, or a private roadway at grade, including sidewalks and pathways at or associated with the crossing.
Highway-User Tax	A charge levied on persons or organizations based on their use of public roads. Funds collected are usually applied toward highway construction, reconstruction, and maintenance.
Historic Preservation	Protection and treatment of the nation's significant historic buildings, landmarks, landscapes, battlefields, tribal communities, and archeological sites; prominent federally-owned buildings; and State and privately-owned properties. [National Park Service, Historic Preservation Services]
Hit and Run	(See also Crash) A hit-and-run occurs when a motor vehicle in transport, or its driver, departs from the scene after being involved in a crash prior to police arrival on the scene. Fleeing pedestrians and motor vehicles not in transport are excluded from the definition. It does not matter whether the hit-and-run vehicle was striking or struck. (NHTSA1)
Hobo	Tractor that is shifted from terminal to terminal. (ATA1)
Hold For Release	Used by Air Traffic Control (ATC) to delay an aircraft for traffic management reasons; i.e., weather, traffic volume, etc. Hold for release instructions (including departure delay information) are used to inform a pilot or a controller (either directly or through an authorized relay) that an Instrument Flight Rules (IFR) departure clearance is not valid until a release time or additional instructions have been received. (FAA4)
Hold Open	To hold below or above an object (i.e., wide of the mark) being steered on, depending on direction. Upstream tows normally hold above, downstream tows below, the object. (TNDOT1)
Holding Agency	A federal agency having accountability for motor vehicles owned by the Government. This term applies when a federal agency has authority to take possession of, assign or reassign motor vehicles regardless of which agency is using the motor vehicles. (GSA2)
Holding Mark	An object, usually an aid to navigation, on which the pilot of a tow will steer. (TNDOT1)
Holding On	Steering steadily on a mark or object. (TNDOT1)
Home Base	The location where a vehicle is usually parked when not in use or on the road. (BOC4)
Home Signal	A roadway signal at the entrance to a route or block to govern trains in entering and using that route or block. (49CFR236)
Homing	The procedure of using the direction finding equipment of one radio station with the emission of another radio station, where at least one of the stations is mobile, and whereby the mobile station proceeds continuously towards the other station. (FAA4)
Hood Lifter	Garage mechanic. (ATA1)
Hopper	A top loading, funnel-shaped structure for temporary storage of loose materials, which will be dispensed from the bottom. (DOI4)
Hopper Barge	An open-compartment barge used for dry bulk cargo that does not require protection from the weather. (TNDOT1)
Hopper Body	Truck body capable of discharging its load through a bottom opening without tilting. (ATA1)
Horse	Tractor or power unit. (ATA1)
Horse Light	Spotlight mounted on cab to reveal open-range livestock. (ATA1)
Horse Van Body	Truck designed for the transportation of valuable horses (livestock). (ATA1)
Horsepower (HP)	The amount of work that an engine can perform within a given time. One horsepower equals 33,000 foot pounds of work per minute. (GSA2)
Hot Load	Rush shipment of cargo. (ATA1)
Hot-Deck Imputation	A statistical procedure for deriving a probable response to a questionnaire item concerning a household or vehicle, where no response was given during the survey. To perform the procedure, the households or vehicles are sorted by variables related to the missing item. Thus, a series of "sort categories" are formed, which are internally homogeneous with respect to the sort variables. Within each category, households or vehicles for which the questionnaire item is not missing are randomly selected to serve as "donors" to supply values for the missing item of "recipient" households or vehicles. (DOE4)
Household	A group of persons whose usual place of residence is a specific housing unit; these persons may or may not be related to each other. The total of all U.S. households represents the total civilian non-institutionalized population. Does not include group quarters (i.e., 10 or more persons living together, none of whom are related). (FHWA3)
Household Trip	One or more household members traveling together. (FHWA3)
Household Vehicle	A motorized vehicle that is owned, leased, rented or company owned and available to be used regularly by household members during the travel period. Includes vehicles used solely for business purposes or business owned vehicles if kept at home and used for the home to work trip, (e.g., taxicabs, police cars, etc.) which may be owned by, or assigned to, household members for their regular use. Includes all vehicles that were owned or available for use by members of the household during the travel period even though a vehicle may have been sold before the interview. Excludes vehicles that were not working and not expected to be working within 60 days, and vehicles that were purchased or received after the designated travel day. (FHWA3)
Housing Unit	A house, apartment, a group of rooms, or a single room occupied or intended for occupancy as separate living quarters. Separate living quarters are those in which the occupants do not live and eat with any other persons in the structure and which have either 1) direct access from the outside of the building or through a common hallway intended to be used by the occupants of another unit or by the general public, or 2) complete kitchen facilities for the exclusive use of the occupants. The occupants may be a single family, one person living alone, two or more families living together, or any other group of related or unrelated persons who share living arrangements. (DOE6)
Hover Check	Used to describe when a helicopter/ Vertical Takeoff and Landing (VTOL) aircraft requires a stabilized hover to conduct a performance/power check prior to hover taxi, air taxi, or takeoff. Altitude of the hover will vary based on the purpose of the check. (FAA4)
Hover Taxi	Used to describe a helicopter/Vertical Takeoff and Landing (VTOL) aircraft movement conducted above the surface and in ground effect at airspeeds less than approximately 20 knots. The actual height may vary, and some helicopters may require hover taxi above 26 feet above ground level (AGL) to reduce ground effect turbulence or provide clearance for cargo slingloads. (FAA4)
How Do You Hear Me?	A question relating to the quality of the transmission or to determine how well the transmission is being received. (FAA4)
Hull Inspector	Colloquial river term for any large piece of drift or submerged piling, log, rock etc. (TNDOT1)
Human Factor	(See also Employee Human Factor) Behavior affecting elements of railroad employee job performance. (FRA3)
Humping	The process of connecting a moving rail car with a motionless rail car within a rail classification yard in order to make up a train. The cars move by gravity from an incline or "hump" onto the appropriate track. (MARAD2)
Hurdle	(See also Dike) A colloquial term for a dike. (TNDOT1)
Hydraulic Head	The distance between the respective elevations of the upstream water surface (headwater) above and the downstream surface water (tailwater) below a hydroelectric power plant. (DOE5)
Hydrocarbon	A compound that contains only hydrogen and carbon. The simplest and lightest forms of hydrocarbon are gaseous. With greater molecular weights, they are liquid, while the heaviest are solids. (DOE6)
Hydrocarbons (HC)	Colorless gaseous compounds originating from evaporation and the incomplete combustion of fossil fuels.
Hyphenated Point	Basically two or more neighboring communities which, in terms of authorization shown in a carrier's Certificate of Public Convenience and Necessity, are treated as a single community. (FAA15)
I Say Again	The message will be repeated. (FAA4)
Ice Action On Bridge Piers	The force required to break ice, transmitted to bridge piers and other structures in the river. Such a force could damage the structures. (TNDOT1)
Ice Clause	A standard clause in the chartering of ocean vessels. It dictates the course a vessel master may take if the ship is prevented from entering the loading or discharging port because of ice, or if the vessel is threatened by ice while in the port. The clause establishes right and obligations of both vessel owner and charterer if these events occur. (USTTA1)
Ice Gorge	A conglomeration of ice solidly packed from bank to bank which is obstructing the flow of the river and marine traffic. (TNDOT1)
Ice Pier	A heavily constructed cluster of piling or concrete behind which towboats moor or shelter from running ice. (TNDOT1)
Ice Shelf	Seaward extension of an ice sheet, floating but attached to the land on at least one side and bounded on the seaward side by a steep cliff rising 2 to 50 m or more above sea level. (DOI3)
Iceberg	A large mass of detached land ice in the sea or stranded in shallow water. (DOI4)
Ident	(See also Identification) A request for a pilot to activate the aircraft transponder identification feature. This will help the controller to confirm an aircraft identity or to identify an aircraft. (FAA4)
Ident Feature	The special feature in the Air Traffic Control Radar Beacon System (ATCRBS) equipment. It is used to immediately distinguish one displayed beacon target from other beacon targets. (FAA4)
Identification	See also Ident.
Identification Lamps	Lamps used to identify certain types of commercial motor vehicles. (49CFR393)
Idle Thrust	The jet thrust obtained with the engine power control level set at the stop for the least thrust position at which it can be placed. (14CFR1)
If No Transmission Received For (Time)	Used by Air Traffic Control (ATC) in radar approaches to prefix procedures which should be followed by the pilot in event of lost communications. (FAA4)
Immediately	Used by Air Traffic Control (ATC) when such action compliance is required to avoid an imminent situation. (FAA4)
Imports	Receipts of goods into the 50 States and the District of Columbia from foreign countries and from Puerto Rico, the Virgin Islands, and other U.S. possessions and territories. (DOE3)
Impounding Space	A volume of space formed by dikes and floors which is designed to confine a spill of hazardous liquid. (49CFR193)
Impounding System	Includes an impounding space, including dikes and floors for conducting the flow of spilled hazardous liquids to an impounding space. (49CFR193)
Improper Loading	Loading, including weight shifting, of a vessel causing instability, limited maneuverability, or dangerously reduced freeboard. (USCG2)
Improper Lookout	No proper watch; the failure of the operator to perceive danger because no one was serving as lookout, or the person so serving failed in that regard. (USCG2)
In bond Shipment	A shipment status in which goods are permitted to enter a country and temporarily stored for transport to a final destination where the duty will be paid.
In Bulk	The transportation, as cargo, of property, except Class A and B explosives and poison gases, in containment systems with capacities in excess of 3,500 water gallons. (49CFR387)
In Draft	Current moving across the lock entrance toward the shore. (TNDOT1)
In Shape	Term used when a tow is properly aligned for entering a lock or passing through a narrow channel or opening between bridge piers. (TNDOT1)
In the Marks	Proceeding along the channel line as described in the channel report. Well on the line (imaginary) running from one mark to the other or from one light to the other. (TNDOT1)
Inactive Aircraft	All legally registered civil aircraft which flew zero hours. (FAA2) (FAA9)
Inboard-Outboard	Also referred to as inboard/outdrive. Regarded as inboard because the power unit is located inside the boat. (USCG2)
Incapacitating Injury	Any injury, other than a fatal injury, that prevents the injured person from walking, driving, or normally continuing the activities the person was capable of performing before the injury occurred. Includes severe lacerations, broken or distorted limbs, skull or chest injuries, abdominal injuries, unconsciousness at or when taken from the accident scene, and inability to leave the accident scene without assistance. Exclusions include momentary unconsciousness.
Incerfa (Uncertainty Phase)	A situation wherein uncertainty exists as to the safety of an aircraft and its occupants. (FAA4)
Incident	Collisions, derailments, personal casualties, fires, and property damage in excess of $1000, associated with transit agency revenue vehicles; all other facilities on the transit property; and service vehicles, maintenance areas and rights-of-way (ROW). (FTA1) (FTA2)
Incident (Hazardous Materials)	Any unintentional release of hazardous material while in transit or storage.
Incident (Train)	Any event involving the movement of a train or railcars on track equipment that results in a death, a reportable injury, or illness, but in which railroad property damage does not exceed the reporting threshold.
Incident (Transit)	Collisions, derailments, personal casualties, fires, and property damage in excess of $1,000 associated with transit agency revenue vehicles; all other facilities on the transit property; and service vehicles, maintenance areas, and rights-of-way.
Incident Reporting Thresholds	For an incident to be reportable, it must involve a transit vehicle or occur on transit property, and result in death, injury, or property damage in excess of $1,000. (FTA1)
Incline Railway	Railway used to traverse steep slopes. (DOI3)
Inclined Plane	A railway operating over exclusive right-of-way on steep grades with unpowered vehicles propelled by moving cables attached to the vehicles and powered by engines or motors at a central location not on board the vehicle. (APTA1)
Inclined Plane Vehicles	Special type of passenger vehicles operating up and down slopes on rails via a cable mechanism. (FTA1)
Income Taxes For the Period	Provisions for Federal, State, local and foreign taxes, which are based upon net income. (BTS4)
Independent Surveillance	A system which requires no airborne compatible equipment. (FAA8)
Indian Lands	Indian reservation or Indian trust land or restricted Indian land which is not subject to fee title alienation without the approval of the Federal Government, or Indian and Alaska Native villages, group, or communities in which Indians and Alaskan Natives reside, whom the Secretary of the Interior has determined are eligible for services generally available to Indians under Federal laws specifically applicable to Indians.
Indian Reservation Roads (IRR)	Public roads that are located within or provide access to an Indian reservation or Indian trust land or restricted Indian land which is not subject to fee title alienation without the approval of the Federal Government, or Indian and Alaska Native villages, group, or communities in which Indians and Alaskan Natives reside, whom the Secretary of the Interior has determined are eligible for services generally available to Indians under Federal laws specifically applicable to Indians. Roads on the BIA Road System are also IRR roads.
Indian Tribal Government (ITG)	Duly formed governing body of an Indian Tribe.
Indian Tribe	Means any Indian or Alaska Native tribe, band, nation, pueblo, village, or community that the Secretary of the Interior acknowledges to exist as an Indian tribe pursuant to the Federally Recognized Indian Tribe List Act of 1994, 25 U.S.C. 479a.
Indicated Airspeed	The speed of an aircraft as shown on its pitot static airspeed indicator calibrated to reflect standard atmosphere adiabatic compressible flow at sea level uncorrected for airspeed system errors. (14CFR1)
Indication	The information conveyed by the aspect of a signal. (49CFR236)
Indication Locking	[with respect to rail operations] Electric locking which prevents manipulation of levers that would result in an unsafe condition for a train movement if a signal, switch, or other operative unit fails to make a movement corresponding to that of its controlling lever, or which directly prevents the operation of a signal, switch, or other operative unit, in case another unit which should operate first fails to make the required movement. (49CFR236)
Indirect Employment	In respect to waterways industry not necessarily engaged directly in river activities, but dependent upon the river. (TNDOT1)
Inductor	A track element consisting of a mass of iron, with or without a winding, that simulates the train control, train stop, or cab signal mechanisms on the rail vehicle. (TRB1)
Industrial Sector	Construction, manufacturing, agricultural and mining establishments. (DOE6)
Industrial Special	Any use of an aircraft for specialized work allied with industrial activity, excluding transportation and aerial application eg. pipeline patrol, survey, advertising, photography, helicopter hoist, etc. (FAA10)
Industrial Terminal	A specialized terminal whose primary purpose is manufacturing, not transportation services. (TNDOT1)
Industrial Track	A switching track serving industries, such as mines, mills smelters, and factories. (49CFR245)
Industry Briefing	Appearance of Coast Guard standards trained personnel before a gathering of boat and\or associated equipment manufacturers and/or dealers. (USCG1)
Industry Track	A switching track, or series of tracks, serving the needs of a commercial industry other than a railroad. (FRA2)
Inertial Navigation System	An Area Navigation (RNAV) system which is a form of self-contained navigation. (FAA4)
Inflight Survey (IFS)	The Inflight Survey is administered to United States (U.S.) and foreign travelers departing the U.S. as a means of providing data on visitor characteristics, travel patterns and spending habits, and for supplying data on the U.S. international travel dollar accounts as well as to meet balance of payments estimation needs. The Inflight Survey (IFS) covers about 70% of U.S. carriers and 35% of foreign carriers who voluntarily choose to participate. (USTTA1)
Informal Factory Visit	A visit by Coast Guard personnel to a manufacturing facility to acquaint the manufacturer with the existence of the law, regulations, general administrative requirements affecting him, and possible penalties for violations. (USCG1)
Information Request	A request originated by an Flight Service Station (FSS) for information concerning an overdue Visual Flight Rules (VFR) aircraft. (FAA4)
Infrastructure	1) In transit systems, all the fixed components of the transit system, such as rights-of-way, tracks, signal equipment, stations, park-and-ride lots, but stops, maintenance facilities. 2) In transportation planning, all the relevant elements of the environment in which a transportation system operates. (TRB1) 3) A term connoting the physical underpinnings of society at large, including, but not limited to, roads, bridges, transit, waste systems, public housing, sidewalks, utility installations, parks, public buildings, and communications networks.
Initial Approach Fix	The fixes depicted on instrument approach procedure charts that identify the beginning of the initial approach segment(s). (FAA4)
Initial Approach Segment	That segment of an instrument approach procedure between the initial approach fix and the intermediate approach fix or, where applicable, the final approach fix or point. (FAA4)
Initial Impact Point	The first impact point that produced property damage or personal injury, regardless of First or Most Harmful Event. (NHTSA1) (NHTSA3)
Initial Terminal	The starting point of a locomotive for a trip. (49CFR236)
Injury	1) Bodily injury resulting from a motor vehicle accident. To qualify as an "injury," the injured person must require and receive medical treatment away from the accident scene. 2) Harm to a person resulting from a single event, activity, occurrence, or exposure of short duration. (FHWA2) (FHWA4) (FRA2)
Injury (Air)	See Serious Injury (air carrier/ general aviation).
Injury (Gas)	Described in U.S. Department of Transportation Forms 7100.1 or 7100.2 as an injury requiring “in-patient hospitalization” (admission and confinement in a hospital beyond treatment administered in an emergency room or out-patient clinic in which confinement does not occur).
Injury (Hazardous Liquid Pipeline)	An injury resulting from a hazardous liquid pipeline accident that results in one or more of the following 1) loss of consciousness, 2) a need to be carried from the scene, 3) a need for medical treatment, and/or 4) a disability that prevents the discharge of normal duties or the pursuit of normal duties beyond the day of the accident.
Injury (Highway)	Police-reported highway injuries are classified as follows
Injury (Highway-Rail Grade Crossing)	1) An injury to one or more persons other than railroad employees that requires medical treatment; 2) an injury to one or more employees that requires medical treatment or that results in restriction of work or motion for one or more days, or one or more lost work days, transfer to another job, termination of employment, or loss of consciousness; 3) any occupational illness affecting one or more railroad employees that is diagnosed by a physician.
Injury (Rail)	1) Injury to any person other than a railroad employee that requires medical treatment, or 2) injury to a railroad employee that requires medical treatment or results in restriction of work or motion for one or more workdays, one or more lost workdays, termination of employment, transfer to another job, loss of consciousness, or any occupational illness of a railroad employee diagnosed by a physician.
Injury (Recreational Boating)	Injury requiring medical treatment beyond first aid as a result of an occurrence that involves a vessel or its equipment.
Injury (Transit)	Any physical damage or harm to a person requiring medical treatment or any physical damage or harm to a person reported at the time and place of occurrence. For employees, an injury includes incidents resulting in time lost from duty or any definition consistent with a transit agency’s current employee injury reporting practice.
Injury (Water)	All personal injuries resulting from a vessel casualty that require medical treatment beyond first aid.
Injury Accident	An accident for which at least one injury, but no fatalities, was reported. (FHWA2) (FHWA4)
Injury Crash	A police-reported crash that involves a motor vehicle in transport on a trafficway in which no one died but at least one person was reported to have 1) An incapacitating injury; 2) A visible but not incapacitating injury; 3) A possible, not visible injury; or 4) An injury of unknown severity. (NHTSA3) (NHTSA4)
Injury Index	Refers to the highest degree of personal injury sustained as a result of the accident. (NTSB1) (NTSB2)
Injury Rate	The average number of nonfatal injuries per accident or per one hundred accidents. (FHWA4)
Injury Severity	The police-reported injury severity of the occupant, pedestrian, or pedalcyclist (e.g., severe or fatal; killed or incapacitating; minor or moderate; evident, but not incapacitating; complaint of injury; injured, severity unknown; no injury). (NHTSA1)
Inland	Means transit to and from inland ports connected by water routes made navigable by one or more lock structures. (SLSDC1)
Inland And Coastal Channels	Includes the Atlantic Coast Waterways, the Atlantic Intracoastal Waterway, the New York State Barge Canal System, the Gulf Coast Waterways, the Gulf Intracoastal Waterway, the Mississippi River System (including the Illinois Waterway), the Pacific Coast Waterways, the Great Lakes, and all other channels (waterways) of the United States, exclusive of Alaska, that are usable for commercial navigation.
Inland and Coastal Channels and Waterways	These terms include the Atlantic Coast Waterways, the Atlantic Intracoastal Waterway, the New York State Barge Canal System, the Gulf Coast Waterways, the Gulf Intracoastal Waterway, the, Mississippi River System (including the Illinois Waterway), Pacific Coast Waterways, the Great Lakes, and all other channels (waterways) of the United States, exclusive of Alaska, that are usable for commercial navigation. (TNDOT1)
Inland Area	The area shoreward of the boundary lines defined in 46 CFR 7, except that in the Gulf of Mexico, it means the area shoreward of the lines of demarcation (COLREG lines) defined in 33 CFR 80.740-80.850. The inland area does not include the Great Lakes. (49CFR194)
Inland Bill of Lading	A bill of lading used in transporting goods overland to the exporter's international carrier. Although a through bill of lading can sometimes be used, it is usually necessary to prepare both an inland bill of lading and an ocean bill of lading for export shipments. (USTTA1)
Inland Carrier	A transportation line that hauls export or import traffic between ports and inland points. (MARAD2)
Inland Navigation Facility	A navigation aid on a North American Route at which the common route and/or the noncommon route begins or ends. (FAA4)
Inland Waterway Convoy	One or more non-powered Inland Waterways Transport (IWT) vessels which are towed or pushed by one or more powered IWT vessels. (TNDOT1)
Inland Waterway Journey	Any movement of an Inland Waterways Transport (IWT) vessel from a specified point of origin to a specified point of destination. (TNDOT1)
Inland Waterway of the United States	Any improved waterway, the improvements to which are primarily for the use of vessels other than ocean going vessels. (TNDOT1)
Inland Waterway Transport (IWT)	Any movement of goods and/or passengers using an IWT vessel on a given inland waterways network. (TNDOT1)
Inland Waterways Cabotage Transport	National Inland Waterways Transport (IWT) performed by an IWT vessel registered in another country. (TNDOT1)
Inland Waterways Fleet	Number of Inland Waterways Transport (IWT) vessels registered at a given date in a country and authorized to use inland waterways open for public navigation. (TNDOT1)
Inland Waterways On National Territory Traffic	Any movement of an Inland Waterways Transport (IWT) vessel within a national territory irrespective of the country in which the vessel is registered. (TNDOT1)
Inland Waterways Passenger	Any person who makes a journey on board of an Inland Waterways Transport (IWT) vessel. Service staff assigned to IWT vessels are not regarded as passengers. (TNDOT1)
Inland Waterways Passenger Transport Link	The combination of the place of embarkment and the place of disembarking of the passenger conveyed by inland waterways whichever itinerary is followed. (TNDOT1)
Inland Waterways Passenger-Kilometer	Unit of measure representing the transport of one passenger by inland waterway over one kilometer. (TNDOT1)
Inland Waterways Traffic	Any movement on an Inland Waterways Transport (IWT) vessel on a given network. (TNDOT1)
Inland Waterways Transit	Inland Waterways Transport (IWT) through a country between two places (a place of loading and a place of unloading) both located in another country or in other countries provided the total journey within the country is by an IWT vessel and that there is no loading and unloading in that country. (TNDOT1)
Inland Waterways Transport (IWT) Enterprise	Enterprise carrying out in one or more places activities for the production of IWT services using IWT vessels and whose main activities according to the value added is inland waterway transport and services allied to inland waterway transport. (TNDOT1)
Inland Waterways Transport (IWT) Freight Vessel	Vessel with a carrying capacity of not less than 20 tons designed for the carriage of freight by navigable inland waterways. (TNDOT1)
Inland Waterways Transport (IWT) Passenger Vessel	Vessel designed exclusively or primarily for the public carriage or passengers by navigable inland waterways. (TNDOT1)
Inland Waterways Transport (IWT) Vessel	Floating craft designed for the carriage of goods or public transport of passengers by navigable inland waterways. (TNDOT1)
Inland Zone	The environment inland of the coastal zone excluding the Great Lakes, Lake Champlain, and specified ports and harbors on inland rivers. The term inland zone delineates an area of federal responsibilities for response actions. Precise boundaries are determined by agreements between the Environmental Protection Agency (EPA) and the United States Coast Guard (USCG) and are identified in Federal Regional Contingency Plans. (49CFR194)
Inlet	An opening of the sea into the land or of a lake into its shore. (DOI4)
Inner Marker (IM)	A marker beacon used with an Instrument Landing System (ILS) (CAT II) precision approach located between the middle marker and the end of the ILS runway, transmitting a radiation pattern keyed at six dots per second and indicating to the pilot, both aurally and visually, that he is at the designated decision height (DH), normally 100 feet above the touchdown zone elevation, on the ILS CAT II approach. It also marks progress during a CAT III approach. (FAA4)
Inner Packaging	A packaging for which an outer packaging is required for transport. It does not include the inner receptacle of a composite packaging. (49CFR171)
Inner Receptacle	A receptacle which requires an outer packaging in order to perform its containment function. The inner receptacle may be an inner packaging of a combination packaging or the inner receptacle of a composite packaging. (49CFR171)
Inner-Approach Obstacle Free Zone (OFZ)	(See also Inner-Transitional Obstacle Free Zone, Obstacle Free Zone, Runway Obstacle Free Zone) The inner-approach Obstacle Free Zone (OFZ) is a defined volume of airspace centered on the approach area. The inner-approach OFZ applies only to runways with an approach lighting system. The inner-approach OFZ begins 200 feet from the runway threshold at the same elevation as the runway threshold and extends 200 feet beyond the last light unit in the approach lighting system. The width of the inner approach OFZ is the same as the runway OFZ and rises at a slope of 50 (horizontal) to 1 (vertical) from the beginning. (FAA4) (FAA12)
Inner-Transitional Obstacle Free Zone (OFZ)	(See also Inner-Approach Obstacle Free Zone, Obstacle Free Zone, Runway Obstacle Free Zone) The inner transitional surface Obstacle Free Zone (OFZ) is a defined volume of airspace along the sides of the runway and inner-approach OFZ and applies only to precision instrument runways. The inner-transitional surface OFZ slopes 3 (horizontal) to 1 (vertical) out from the edges of the runway OFZ and inner-approach OFZ to a height of 150 feet above the established airport elevation. (FAA4) (FAA12)
In-Out Racks	Dry land boat storage on a vertical rack system. (BOC2)
Inshore Traffic Zone	A designated area between the landward boundary of a traffic separation scheme and the adjacent coast, intended for local traffic. (DOI4)
Inspection and Maintenance (I/M)	An emissions testing and inspection program implemented by States in nonattainment areas to ensure that the catalytic or other emissions control devices on in-use vehicles are properly maintained.
Inspection and Weighing Services For Motor Vehicle Transport Facility	Establishments primarily engaged in the operation of fixed facilities for motor vehicle transportation, such as toll roads, highway bridges, and other fixed facilities, except terminals. (BOC1)
Instructional Flying	Any use of an aircraft for the purpose of formal instruction with the flying instructor aboard, or with the maneuvers on the particular flight(s) specified by the flight instructor; excludes proficiency flying. (FAA2) (FAA9) (FAA14)
Instrument	A device using an internal mechanism to show visually or aurally the attitude, altitude, or operation of an aircraft or aircraft part. It includes electronic devices for automatically controlling an aircraft in flight. (14CFR1)
Instrument Approach	A series of predetermined maneuvers for the orderly transfer of an aircraft under instrument flight conditions from the beginning of the initial approach to a landing, or to a point from which a landing may be made visually. An instrument approach is prescribed and approved for a specific airport by competent authority Federal Aviation Regulation (FAR) Part 91. (FAA14)
Instrument Approach Procedure	(See also Cruise) A series of predetermined maneuvers by reference to flight instruments with specified protection from obstacles from the initial approach fix, or where applicable, from the beginning of a defined arrival route to a point from which a landing can be completed and thereafter, if a landing is not completed, to a position at which holding or en route obstacle clearance criteria apply. (FAA4)
Instrument Approach Procedures (IAP) Charts	Portrays the aeronautical data which is required to execute an instrument approach to an airport. These charts depict the procedures, including all related data, and the airport diagram. Each procedure is designated for use with a specific type of electronic navigation system including nondirectional beacon (NDB), tactical aircraft control and navigation (TACAN), very high frequency omnidirectional range (VOR), instrument landing system/microwave landing system (ILS/MLS), and area navigation (RNAV). These charts are identified by the type of navigational aid(s) which provide final approach guidance. (FAA4)
Instrument Flight Rules (IFR)	Rules governing the procedures for conducting instrument flight. Also a term used by pilots and controllers to indicate type of flight plan. (FAA2) (FAA4) (FAA6) (FAA13) (FAA14)
Instrument Flight Rules (IFR) Aircraft	An aircraft conducting flight in accordance with instrument flight rules (IFR). (FAA8)
Instrument Flight Rules (IFR) Aircraft Handled	The number of Instrument Flight Rules (IFR) departures multiplied by two plus the number of IFR overs. This definition assumes that the number of departures (acceptances, extensions, and originations of IFR flight plans) is equal to the number of landings (IFR flight plans closed). (FAA2) (FAA13) (FAA14)
Instrument Flight Rules (IFR) Conditions	Weather conditions below the minimum for flight under visual flight rules (VFR). (14CFR1)
Instrument Flight Rules (IFR) Departure	An Instrument Flight Rules (IFR) departure includes IFR flights originating in center's area, accepted by the center under SOLE EN ROUTE clearance procedures, and extended by the center. (FAA2) (FAA13) (FAA14)
Instrument Flight Rules (IFR) Over	An Instrument Flight Rules (IFR) flight that originates outside the Air Route Traffic Control Center (ARTCC) area and passes through the area without landing. (FAA2) (FAA13) (FAA14)
Instrument Flight Rules (IFR) Over-The-Top	With respect to the operation of aircraft, means the operation of an aircraft over-the-top on an Instrument Flight Rules (IFR) flight plan when cleared by air traffic control to maintain "visual flight rules (VFR) conditions" or "VFR conditions on top." (14CFR1)
Instrument Flight Rules (IFR) Takeoff Minimums and Departure Procedure	Federal Aviation Regulations, Part 91, prescribes standard takeoff rules for certain civil users. At some airports, obstructions or other factors require the establishment of nonstandard takeoff minimums, departure procedures, or both to assist pilots in
Instrument Flight Service Station (IFSS)	A central operations facility in the flight advisory system, staffed and equipped to control aeronautical point-to-point telecommunications, and air-ground telecommunications with pilots operating over international territory or waters, which provides flight plan following, weather information, search and rescue action, and other flight assistance operations. (FAA2)
Instrument Landing System (ILS)	(See also Glideslope, Localizer, Middle Marker, Outer Marker) A precision instrument approach system which normally consists of the following electronic and visual aids 1) localizer-provides course guidance to the runway; 2) glide slope-provides vertical guidance during approach; 3) marker beacon-provides aural and/or visual identification of a specific position along an instrument approach landing. (FAA6)
Instrument Landing System Category	1) Instrument Landing System (ILS) Category I. An ILS approach procedure which provides for approach to a height above touchdown of not less than 200 feet and with runway visual range of not less than 1,800 feet. 2) ILS Category II. An ILS approach procedure which provides for approach to a height above touchdown of not less than 100 feet and with runway visual range of not less than 1,200 feet. 3) ILS Category III a) IIIA. An ILS approach procedure which provides for approach without a decision height minimum and with runway visual range of not less than 700 feet. b) IIIB.-An ILS approach procedure which provides for approach without a decision height minimum and with runway visual range of not less than 150 feet. c) IIIC.-An ILS approach procedure which provides for approach without a decision height minimum and without runway visual range minimum. (FAA4)
Instrument Meteorological Conditions (IMC)	Meteorological conditions expressed in terms of visibility, distance from cloud, and ceiling less than the minima specified for visual meteorological conditions. (FAA4)
Instrument Operation	Arrivals or departures of an aircraft in accordance with an Instrument Flight Rules (IFR) flight plan or Special Visual Flight Rules (SVFR) procedures or an operation where Instrument Flight Rules (IFR) separation between aircraft is provided by a terminal control facility. There are three kinds of instrument operations 1) Primary Instrument Operations arrivals and departures at the primary airport which is normally the airport at which the approach control facility is located. 2) Secondary Instrument Operations arrivals and departures at all the secondary airports combined. 3) Overflights operations in which an aircraft transits the area without intent to land. (FAA2) (FAA13) (FAA14)
Instrument Operations	Arrivals or departures of an aircraft in accordance with an IFR flight plan or special VFR procedures or an operation where IFR separation between aircraft is provided by a terminal control facility. (FAA3)
Instrument Practice Approach	An instrument approach procedure conducted by a Visual Flight Rules (VFR) or an Instrument Flight Rules (IFR) aircraft for the purpose of pilot training or proficiency demonstrations. (FAA4)
Instrument Runway	A runway equipped with electronic and visual navigation aids for which a precision or nonprecision approach procedure having straight in landing minimums has been approved. (FAA4)
Instruments of International Traffic	Lift vans, cargo vans, shipping tanks, skids, pallets, caul boards, and cores for textile fabrics, arriving (whether loaded or empty) in use or to be used in the shipment of merchandise in international traffic. (USTTA1)
Insulated Body	Truck or trailer designed for transportation of commodities at controlled temperatures. It may be equipped for refrigeration or heating. (ATA1)
Insulated Rail Joint	A joint in which electrical insulation is provided between adjoining rails. (49CFR236)
Insured and Principal	The motor carrier named in the policy of insurance, surety bond, endorsement, or notice of cancellation, and also the fiduciary of such motor carrier. (49CFR387)
Integrated Carriers	Carriers that have both air and ground fleets; or other combinations, such as sea, rail, and truck. Since they usually handle thousands of small parcels an hour, they are less expensive and offer more diverse services than regular carriers. (USTTA1)
Integrated Gas Company	A company that obtains a significant portion of its gas operating revenues from the operations of both a retail gas distribution system and gas transmission system. An integrated company obtains less than 90 percent but more than 10 percent of its gas operating revenues from either its retail or transmission operations or does not meet the classification of mains established for distribution. (AGA1)
Integrated Tow	Barges designed to fit together so the underwater configuration is the equivalent of a single hull of a motorized vessel. This eliminates water turbulence and increases efficiency. (TNDOT1)
Integrated Transportation	See Intermodalism Definition No. 3.
Integrated Transportation and Land-Use Package (ITLUP)	The Institute of Transportation Engineers (ITE), an international individual member educational and scientific association, is one of the largest and fastest-growing multimodal professional transportation organizations in the world. ITE members are traffic engineers, transportation planners and other professionals who are responsible for meeting society's needs for safe and efficient surface transportation through planning, designing, implementing, operating and maintaining surface transportation systems worldwide.
Intelligent Transportation Systems (ITS)	The application of advanced technologies to improve the efficiency and safety of transportation systems.
Interagency Fleet Management System (IFMS)	The organizational title assigned to the General Services Administrations (GSA) interagency fleet operation which encompasses the Central Office, Regional Offices, and all Fleet Management Centers and Fleet Management Subcenters. (GSA2)
Intercept Glideslope Altitude	(See also Glideslope) The minimum altitude to intercept the glideslope/path on a precision approach. The intersection of the published intercept altitude with the glideslope/path, designated on Government charts by the lightning bolt symbol, is the precision Final Approach Fix (FAF). However, when Air Traffic Control (ATC) directs a lower altitude, the resultant lower intercept position is then the FAF. (FAA4)
Interchange	An area designated to provide traffic access between roadways of differing levels. (DOI3)
Intercity and Rural Bus Transportation	Establishments primarily engaged in furnishing bus transportation, over regular routes and on regular schedules, the operations of which are principally outside a single municipality and its suburban areas. (BOC1)
Intercity Bus	A bus with front doors only, high-backed seats, separate luggage compartments, and usually with restroom facilities for use in high-speed long-distance service. (APTA1)
Intercity Class I Bus	As defined by the Bureau of Transportation Statistics, an interstate motor carrier of passengers with an average annual gross revenue of at least $1 million.
Intercity Passenger Mile	The distance generated by moving one passenger one mile on a trip between two cities. (TNDOT1)
Intercity Rail Passenger	A rail car, intended for use by revenue passengers, obtained by the National Railroad Passenger Corporation (currently AMTRAK) for use in intercity rail transportation. (49CFR37)
Intercity Rail Transportation	Transportation provided by Amtrak. (49CFR37)
Intercity Transportation	1) Transportation between cities. 2) Transportation service provided between cities by certified carriers, usually on a fixed route with a fixed schedule. (TRB1)
Intercity Truck	A truck that carries freight beyond local areas and commercial zones.
Intercity Trucking	Trucking operations which carry freight beyond the local areas and commercial zones. (ATA2)
Interest Long Term Debt and Capital Leases	Interest on all classes of debt, both short-term and long-term, as well as the amortization of premium, discount and expense connected with the issuance of such debt and interest expense on capital leases. (BTS4)
Interfacility	Between adjacent facilities; between Air Control Facility (ACF) and ACF, or between ACF and Air Traffic Control Tower (ATCT), as contrasted with intrafacility. (FAA8)
Intergovernmental Revenue	Amounts received from other governments as fiscal aid in the form of shared revenues and grants-in-aid, as reimbursements for performance of general government functions and specific services for the paying government, or in lieu of taxes. This revenue excludes amounts received from other governments for sale of property, commodities and utility services. (BTS3)
Interior Compartment Door	Any door in the interior of the vehicle installed by the manufacturer as a cover for storage space normally used for personal effects. (49CFR571)
Interline Freight	Freight moving from point of origin to destination over the lines of two or more transportation lines.
Interlocked Route	A route within interlocking limits. (49CFR236)
Interlocked Switch	A switch within the interlocking limits the control of which is interlocked with other functions of the interlocking. (49CFR236)
Interlocking Limits	The tracks between the opposing home signals of an interlocking. (49CFR218) (49CFR236)
Interlocking Machine	An assemblage of manually operated levers or other devices for the control of signals, switches or other units. (49CFR236)
Interlocking Signal	A roadway signal which governs movements into or within interlocking limits. (49CFR236)
Intermediate Approach Segment	That segment of an instrument approach procedure between either the intermediate approach fix and the final approach fix or point, or between the end of a reversal, race track or dead reckoning track procedure and the final approach fix or point, as appropriate. (FAA4)
Intermediate Fix (IF)	The fix that identifies the beginning of the intermediate approach segment of an instrument approach procedure. The fix is not normally identified on the instrument approach chart as an IF. (FAA4)
Intermediate Grade Gasoline	An increasingly common grade of unleaded gasoline with an octane rating intermediate between "regular" and "premium". Octane boosters are added to gasolines to control engine pre-ignition or "knocking" by slowing combustion rates. (DOE4) (DOE5)
Intermediate Landing	On the rare occasion that this option is requested, it should be approved. The departure center, however, must advise the Air Traffic Control Command Center (ATCCC) so that the appropriate delay is carried over and assigned at the intermediate airport. An intermediate landing airport within the arrival center will not be accepted without coordination with and the approval of the ATCCC. (FAA4)
Intermediate Type Road Surface	Mixed bituminous and bituminous penetration (Surface/Pavement Type Codes 52 and 53). (FHWA2)
Intermittent, Casual, or Occasional Driver	A driver who in any period of 7 consecutive days is employed or used as a driver by more than a single motor carrier. The qualification of such a driver shall be determined and recorded in accordance with the provisions of 49 CFR 391.63 or 391.65 as applicable. (49CFR390)
Intermodal	The ability to connect, and the connections between, modes of transportation.
Intermodal Container	A freight container designed and constructed to permit it to be used interchangeably in two or more modes of transport. (49CFR171)
Intermodal Passenger Terminal	An existing railroad passenger terminal which has been or may be modified as necessary to accommodate several modes of transportation, including intercity rail service and some or all of the following intercity bus, commuter rail, intra-city rail transit and bus transportation, airport limousine service and airline ticket offices, rent-a-car facilities, taxis, private parking, and other transportation services. (49CFR256)
Intermodal Portable Tank	A specific class of portable tanks designed primarily for international intermodal use. (49CFR171)
Intermodal Surface Transportation Efficiency Act of 1991 (ISTEA)	Legislative initiative by the U.S. Congress that restructured funding for transportation programs. ISTEA authorized increased levels of highway and transportation funding from FY92-97 and increased the role of regional planning commissions/MPOs in funding decisions. The Act also required comprehensive regional and Statewide long-term transportation plans and places an increased emphasis on public participation and transportation alternatives.
Intermodal Transport	Enables cargo to be consolidated into economically large units (e.g., containers, bulk grain railcars) optimizing use of specialized intermodal handling equipment to effect high-speed cargo transfer between ships, barges, railcars, and truck chassis using a minimum of labor to increase logistic flexibility, reduce consignment delivery times, and minimize operating costs. (MARAD1)
Intermodal Transportation	Use of more than one type of transportation; e.g., transporting a commodity by barge to an intermediate point and by truck to destination. (TNDOT1)
Intermodalism	Typically used in three contexts 1) most narrowly, it refers to containerization, piggyback service, or other technologies that provide the seamless movement of good and people by more than one mode of transport. 2) more broadly, intermodalism refers to the provision of connections between different modes, such as adequate highways to ports or bus feeder services to rail transit. 3) In its broadest interpretation, intermodalism refers to a holistic view of transportation in which individual modes work together or within their own niches to provide the user with the best choices of service, and in which the consequences on all modes of policies for a single mode are considered. This view has been called balanced, integrated, or comprehensive transportation in the past. (BTS2)
Internal Combustion Engine	An engine in which the power is developed through the expansive force of fuel that is fired or discharged within a closed chamber or cylinder. (TRB1)
Internal Traffic	See Internal Water Transportation.
Internal Traffic (Water)	Vessel movements (origin and destination) that take place solely on inland waterways located within the boundaries of the contiguous 48 states or within the state of Alaska. Internal traffic also applies to carriage on both inland waterways and the water on the Great Lakes; carriage between offshore areas and inland waterways; and carriage occurring within the Delaware Bay, Chesapeake Bay, Puget Sound, and the San Francisco Bay, which are considered internal bodies of water rather than arms of the ocean.
Internal Water Transportation	Includes all local (intraport) traffic and traffic between ports or landings wherein the entire movement takes place on inland waterways. Also termed internal are movements involving carriage on both inland waterways and the water of the Great Lakes, and inland movements that cross short stretches of open water that link inland systems. (DOE6)
International	Traffic (passengers and freight) performed between the designated airport and an airport in another country or territory. (ACI1)
International Air Operator	Commercial air transportation outside the territory of the United States, including operations between the U.S. and foreign countries and between the U.S. and its territories and possessions. (DOE6)
International Air Transportation Association (IATA) (IATA)	Established in 1945, a trade association serving airlines, passengers, shippers, travel agents, and governments. The association promotes safety, standardization in forms (baggage checks, tickets, weight bills), and aids in establishing international airfares. International Air Transportation Association (IATA) headquarters are in Geneva, Switzerland. (USTTA1)
International Airport	1) Any airport designated by the Contracting State in whose territory it is situated as an airport of entry and departure for international air traffic. 2) An airport of entry which has been designated by the Secretary of Treasury or Commissioner of Customs as an international airport for customs service. 3) A landing rights airport at which specific permission to land must be obtained from customs authorities in advance of contemplated use. 4) Airports designated under the Convention on International Civil Aviation as an airport for use by international commercial air transport and/or international general aviation. (FAA4)
International and Territorial Operations	The operation of aircraft flying between the 50 United States and foreign points, between the 50 United States and U.S. possessions and territories, and between two foreign points. Includes both the combination passenger/cargo and the all-cargo carriers engaged in international and territorial operations. (FAA14)
International Bunkers	Storage compartments, found on vessels and aircraft engaged in international commerce, where fuel to be used by the vessel or aircraft is stored. (DOE5)
International Cargo Handling Coordination Association (ICHCA)	1) Collects, edits and disseminates technical information relating to cargo handling by all modes of transport; 2) Maintains consultative status with the International Standards Organization for the development of standards relating to cargo handling equipment (such as hooks, containers, wire slings, spreaders and pallets); 3) Maintains a library for members' use and 4) Represents members' interests on an international basis. (USTTA1)
International Civil Aviation Organization (ICAO) (ICAO)	A specialized agency of the United Nations whose objective is to develop the principles and techniques of international air navigation and to foster planning and development of international civil air transport. International Civil Aviation organization (ICAO) Regions include (AFI) African Indian Ocean Region, (CAR) Caribbean Region, (EUR) European Region, (MID/ASIA) Middle East/Asia Region, (NAM) North American Region, (NAT) North Atlantic Region, (PAC) Pacific Region, (SAM) South American Region. (FAA4) (USTTA1)
International Civil Aviation Organization Broadcast	A transmission of information relating to air navigation that is not addressed to a specific station or stations. (FAA4)
International Flight Information Manual	A publication designed primarily as a pilot's preflight planning guide for flights into foreign airspace and for flights returning to the U.S. from foreign locations. (FAA4)
International Flight Service Station (IFSS) (IFSS)	A central operations facility in the flight advisory system, manned and equipped to control aeronautical point-to-point telecommunications, and air/ground telecommunications with pilots operating over international territory or waters, providing flight plan filing, weather information, search and rescue action and other flight assistance operations. (FAA14)
International Freight Forwarder	A person, duly registered with the Federal Maritime Board, engaged in the business of dispatching shipments on behalf of other persons, for a consideration, by ocean going vessels in commerce from the United States, its territories, or possessions, and handling the formalities incident to such shipments. (TNDOT1)
International Inland Waterways Transport	Inland waterways transport between two places (a place of loading/embarkment and a place of unloading/disembarking) located in two different countries. It may involve transit through one or more additional countries. (TNDOT1)
International Maritime Organization (IMO) (IMO)	Established as a specialized agency of the United Nations in 1948. The International Maritime Organization (IMO) facilitates cooperation on technical matters affecting merchant shipping and traffic, including improved maritime safety and prevention of marine pollution. Headquarters are in London, England. (USTTA1)
International Maritime Satellite Organization (INMARSAT) (INMARSAT)	An international partnership of signatories from 67 nations. The partnership provides mobile satellite capacity to its signatories, who, in turn, use the capacity to provide worldwide mobile satellite services to their maritime, aeronautical and land-mobile customersincluding shipping, cruise, fishing, research and offshore exploration industries, and airlines. INMARSAT began service in 1976. (USTTA1)
International Operations	In general, operations outside the territory of the U.S., including operations between the U.S. and foreign countries, and the U.S. and its territories or possessions. Includes both the combination passenger/cargo carrier and the all-cargo carriers engaged in international and territorial operations. (FAA2) (FAA15)
International Passenger	Any person traveling on a waterborne public conveyance between the United States and foreign countries and between Puerto Rico and the Virgin Islands and foreign countries. (TNDOT1)
International Transportation	Transportation between any place in the United States and any place in a foreign country; between places in the United States through a foreign country; or between places in one or more foreign countries through the United States. (49CFR171)
Interrogator	The ground-based surveillance radar beacon transmitter-receiver, which normally scans in synchronism with a primary radar, transmitting discrete radio signals which repetitiously request all transponders on the mote being used to reply. The replies received are mixed with the primary radar returns and displayed on the same plan position indicator (radar scope). Also, applied to the airborne element of the TACAN/DME system. (FAA4)
Intersecting Runway	Two or more runways which cross or meet within their lengths. (FAA4)
Intersection	1) A point defined by any combination of courses, radials, or bearings of two or more navigational aids. 2). Used to describe the point where two runways, a runway and a taxiway, or two taxiways cross or meet. (FAA4)
Intersection Departure	A departure from any runway intersection except the end of the runway. (FAA4)
Interstate	Limited access divided facility of at least four lanes designated by the Federal Highway Administration as part of the Interstate System. (NHTSA3)
Interstate Air Commerce	The carriage by aircraft of persons or property for compensation or hire, or the carriage of mail by aircraft, or the operation or navigation of aircraft in the conduct or furtherance of a business or vocation, in commerce between a place in any State of the United States, or the District of Columbia, and a place in any other State of the United States, or the District of Columbia; or between places in the same State of the United States through the airspace over any place outside thereof; or between places in the same territory or possession of the United States, or the District of Columbia. (14CFR1)
Interstate Air Transportation	The carriage by aircraft of persons or property as a common carrier for compensation or hire, or the carriage of mail by aircraft in commerce 1) Between a place in a State or the District of Columbia and another place in another State or the District of Columbia; 2) Between places in the same State through the airspace over any place outside that State; or 3) Between places in the same possession of the United States; whether that commerce moves wholly by aircraft or partly by aircraft and partly by other forms of transportation. (14CFR1)
Interstate Commerce	Trade, traffic, or transportation in the United States which is between a place in a State and a place outside of such State (including a place outside of the United States) or is between two places in a State through another State or a place outside of the United States. (49CFR390)
Interstate Commerce Commission (ICC)	The federal body charged with enforcing Acts of Congress affecting interstate commerce. (ATA2)
Interstate Commerce Commission (ICC) Authorized Carrier	A for-hire motor carrier engaged in interstate or foreign commerce, subject to economic regulation by the ICC. (FHWA4)
Interstate Commerce Commission (ICC) Exempt Carrier	A for-hire motor carrier transporting commodities or conducting operations not subject to economic regulation by the ICC. (FHWA4)
Interstate Highway	Limited access, divided highway of at least four lanes designated by the Federal Highway Administration as part of the Interstate System.
Interstate Highway (Freeway or Expressway)	A divided arterial highway for through traffic with full or partial control of access and grade separations at major intersections. (FHWA3)
Interstate Highway System (IHS)	The system of highways that connects the principal metropolitan areas, cities, and industrial centers of the United States. Also connects the US to internationally significant routes in Canada and Mexico.
Interstate Maintenance (IM)	The Interstate Maintenance (IM) program provides funding for resurfacing, restoring, rehabilitating and reconstructing (4R) most routes on the Interstate System.
Interstate Pipeline	A natural gas pipeline company that is engaged in the transportation, by pipeline, of natural gas across state boundaries, and is subject to the jurisdiction of the Federal Energy Regulatory Commission (FERC) under the Natural Gas Act. (DOE1) (DOE5)
Intrafacility	Within a single facility; for example between two sectors within the same Area Control Facility (ACF), as contrasted with interfacility. (FAA8)
Intransit Deliveries	Redeliveries to a foreign country of foreign gas received for transportation across U.S. territory, and deliveries of U.S. gas to a foreign country for transportation across its territory and redelivery to the United States. (DOE5)
Intransit Passengers	Revenue passengers onboard international flights that transit an airport for non-traffic purposes in the 50 states. (FAA11)
Intransit Receipts	Receipts of foreign gas for transportation across United States (U.S.) territory and redelivery to a foreign country, and redeliveries to the U.S. of U.S. gas transported across foreign territory. (DOE5)
Intrastate	Travel within the same state. (BOC3)
Intrastate Air Transportation	The carriage of persons or property as a common carrier for compensation or hire, by turbojet powered aircraft capable of carrying thirty or more persons, wholly within the same state of the United States. (14CFR1)
Intrastate Commerce	Any trade, traffic, or transportation in any State which is not described in the term "interstate commerce." (49CFR390)
Intrastate Pipeline	A natural gas pipeline company engaged in the transportation, by pipeline, of natural gas not subject to the jurisdiction of the Federal Energy Regulatory Commission (FERC) under the Natural Gas Act. (DOE1) (DOE5)
Intraterritorial Traffic	Traffic between ports in Puerto Rico and the Virgin Islands, which are considered as a single unit. (TNDOT1)
Inundation Area	(See also Basin) An area of land subject to flooding. (DOI3)
In-Use Mile Per Gallon (MPG)	A Miles Per Gallon (MPG) that was adjusted for seasonality and annual miles traveled. (DOE4) (DOE5)
Investments and Special Funds	Investments and advances to investor controlled and other associated companies, notes and receivables not due within one year, investment in securities issued by others, allowance for unrealized gain or loss on noncurrent marketable equity securities, funds not available for current operations, investments in leveraged leases, and net investments in direct financing and sales-type leases which are not reasonably expected to be amortized within one year. (BTS4)
Iron	Old model truck. (ATA1)
Iron Lunger	The conventional 220 or 250 horsepower engine. (ATA1)
IRR Inventory	An inventory of roads which meet the following criteria: a) public roads strictly within reservation boundaries, b) public roads that provide access to lands, to groups, villages, and communities inwhich the majority of residences are Indian, c) public roads that serve Indian lands not within reservation boundaries, and d) public roads that serve recognized Indian groups, villages, and isolated communities not located within a reservation.
IRR Program Stewardship Plan	The plan which details the roles and responsibilities of the BIA, FHWA and ITGs in the administration and operation of the IRR Program.
IRR Road/Bridge Inventory	An inventory of BIA owned IRR and bridges.
IRR TIP	A multi-year listing of road improvement projects programmed for construction by a BIA area office, with IRR Program funds, for the next 3-5 years. A separate IRR TIP is prepared for each State within the area office's jurisdiction.
IRR Transportation Planning Funds	Funds provided under 23 U.S.C., Section 204 (j), for transportation planning by ITGs.
Isolated Rural Nonattainment and Maintenance Areas	Areas that do not contain or are not part of any metropolitan planning area as designated under the transportation planning regulations. Isolated rural areas do not have Federally required metropolitan transportation plans or TIPs and do not have projects that are part of the emissions analysis of any MPO’s metropolitan transportation plan or TIP. Projects in such areas are instead included in statewide transportation improvement programs. These areas are not donut areas.
Itinerant Aircraft Operations	All aircraft operations other than local operations. (FAA13) (FAA14)
J Route	See Jet Route.
Jack Staff	A vertical pole erected on the lead barge of a tow used by the pilot for aligning the heading of the tow. (TNDOT1)
Jacking It Around	Backing a semitrailer around a very sharp curve. (ATA1)
Jackknife	(See also Accident, Rollover) Jackknife can occur at any time during the crash sequence. In this report, jackknifing is restricted to truck tractors pulling a trailing unit in which the trailing unit and the pulling vehicle rotate with respect to each other. (NHTSA3)
Jacob's Ladder	A rope ladder suspended from the side of a vessel and used for boarding. (MARAD2)
Jamming	Electronic or mechanical interference which may disrupt the display of aircraft on radar or the transmission/reception of radio communications/navigation. (FAA4)
Jeep-Like Vehicle	See Sport-Utility Vehicle.
Jet Blast	Jet engine exhaust (thrust stream turbulence). (FAA4)
Jet Down	To sink an object, generally a buoy sinker, deep into the mud below the river bottom by the use of high pressure water jet. (TNDOT1)
Jet Fuel	Includes kerosene-type jet fuel (used primarily for commercial turbojet and turboprop aircraft engines) and naphtha-type jet fuel (used primarily for military turbojet and turboprop aircraft engines).
Jet Route	A route designed to serve aircraft operations from 18,000 feet mean sea level (MSL) up to and including flight level 450. The routes are referred to as "J" routes with numbering to identify the designated route; e.g. J105. (FAA2) (FAA4)
Jet Stream	A migrating stream of high-speed winds present at high altitudes. (FAA4)
Jettisoning of External Stores	(See also Fuel Dumping) Airborne release of external stores; (e.g., tiptanks, ordnance). (FAA4)
Jitney	Passenger cars or vans operating on fixed routes (sometimes with minor deviations) as demand warrants without fixed schedules or fixed stops. (FTA1)
Jockey Line	Lashing used to prevent lateral movement between barges connected in tandem. (TNDOT1)
Johnboat	Flat bottomed skiff type boat with square bow and stern. (TNDOT1)
Joint Operations	Rail operations conducted on a track used jointly or in common by two or more railroads subject to 49 CFR 225 or operation of a train, locomotive, car or other on-track equipment by one railroad over the track of another railroad. (49CFR225) (FRA2)
Joint-Use Airport	A military installation at which the Department of Defense permits some degree of civil aviation use. Degrees of civil aviation use include 1) Open to all civil aviation under a joint-use agreement 2) Joint-use agreement for limited use. Strictly military airports do not qualify for primary or commercial service status. (FAA11)
Joule	Unit of measurement of energy consumption. (TNDOT1)
Jumbo Barge	A barge 35 feet wide by 195 or 200 feet long that may be either a hopper or cover-type barge. (TNDOT1)
Jumped the Pin	Missing the fifth wheel pin on the trailer when coupling tractor to trailer. (ATA1)
Junction	Area formed by the connection of two roadways, including intersections, interchange areas and entrance/exit ramps. (NHTSA3)
Just in Time (JIT)	Cargo or components that must be at a destination at the exact time needed. The container or vehicle is the movable warehouse.
Kanawha River Ratchet	Term for placing toothpick or bar between doubled-up line to bring two barges together by twisting bar around and around. Very dangerous to use. (TNDOT1)
Keelboat	A long, flat bottomed boat with a keel used to haul freight and passengers before the appearance of steamboats on the western rivers. (TNDOT1)
Kerosene	(See also Fuel, Gasoline) A petroleum distillate that boils at a temperature between 300 and 550 degrees Fahrenheit, that has a flash point higher than 100 degrees Fahrenheit by ASTM Method D 56, that has a gravity range from 40 to 46 degrees API, and that has a burning point in the range of 150 degrees to 175 degrees Fahrenheit. Kerosene is used in space heaters, cook stoves, and water heaters and is suitable for use as an illuminate when burned in wick lamps. (DOE2) (DOE5) (DOE6)
Kerosene-Type Jet Fuel	A quality kerosene product with an average gravity of 40.7 degrees API, and a 10 percent distillation temperature of 400 degrees Fahrenheit. It is covered by American Society of Testing Materials (ASTM) Specification D1655 and Military Specification MIL-T-5624L (Grades JP-5 and JP-8). A relatively low-freezing point distillate of the kerosene type; it is used primarily for commercial turbojet and turboprop aircraft engines. (DOE5) (DOE6)
Kevel	Colloquial term used for a large steel cleat secured to the deck of a boat or a barge, used for securing, mooring and towing lines. It is provided with two prongs called "horn." Also spelled "cavil", "cavel", "caval." (TNDOT1)
Kick Down	Shift down to lower gear. (ATA1)
Kick Line	A line used to hold towboat while stern is being backed in so that head will swing out into the stream. (TNDOT1)
Kick the Donuts	Check the tires. (ATA1)
Kidney Buster	Hard riding truck. (ATA1)
Kilometer	See also Mile.
Kilowatt (KW)	(See also Electricity, Gigawatt, Megawatt) One thousand watts. (DOE5)
Kilowatt Electric (KWE)	One thousand watts of electric capacity. (DOE5)
Kilowatt Hour (KWH)	One thousand watt/hours. (DOE5)
King-Pin Saddle-Mount	(See also Lower Half of Saddle-Mount, Saddle-Mount, and Upper Half of Saddle-Mount) That device which is used to connect the "upper-half" to the "lower-half" [of a " saddle-mount"] in such manner as to permit relative movement in a horizontal plane between the towed and towing vehicles. (49CFR393)
Kiss and Ride	A place where commuters are driven and dropped off at a station to board a public transportation vehicle. (APTA1)
Knocked Down	Unassembled freight or merchandise. (ATA1)
Knockout	To release towboat from tow. (TNDOT1)
Knockout Single	To uncouple the towboat and lay alongside the barges for single lockage. Also called single set over. (TNDOT1)
Knot	The unit of speed equivalent to one nautical mile, or 6,080.20 feet per hour or 1.85 kilometers per hour. (TNDOT1)
Kort Nozzles	Cylindrical devices which surround the towboat propellers to increase the maneuverability and efficiency of the towboat. (TNDOT1)
Laboring	The effect of shallow water on the sound or performance of the boat's engine. (TNDOT1)
Lading	Refers to the freight shipped; the contents of a shipment. (MARAD2)
Lagoon	(See also Lake, Levee) A shallow area of salt water separated from the open sea by sand or shingle banks. The sheet of water between an offshore reef, especially of coral, and the mainland. The sheet of water within a ring or horseshoe-shaped atoll. (DOI4)
Lake	Any standing body of inland water. (DOI4)
Lake/Pond	A standing body of water with a predominantly natural shoreline surrounded by land. (DOI3)
Lakewise or Great Lakes	These terms apply to traffic between U.S. ports of the Great Lakes system. The Great Lakes system is treated as a separate system rather than as a part of the inland system. (TNDOT1)
Lakewise Or Great Lakes Traffic	Waterborne traffic between U.S. ports on the Great Lakes system. The Great Lakes system is treated as a separate waterways system rather than as a part of the inland system.
Lamp	A device used to produce artificial light. (49CFR393)
Land	To moor or bring a boat to the riverbank. (TNDOT1)
Land Area	Based on the U.S. Bureau of the Census definition, this includes dry land and land temporarily or partially covered by water, such as marshlands, swamps and river flood plains, systems, sloughs, estuaries and canals less than 1/8 of a statute mile (0.2 kilometers) in width and lakes, reservoirs and ponds less than 1/16 square mile (0.16 square kilometers) in area. [For Alaska, 1/2 mile (0.8 kilometers) and 1 square mile (2.60 square kilometers) are substituted for these values]. The net land area excludes areas of oceans, bays, sounds, etc., lying within the 3 mile (4.8 kilometers) U.S. jurisdiction as well as inland water areas larger than indicated above. (FHWA2)
Land Use	Refers to the manner in which portions of land or the structures on them are used, i.e. commercial, residential, retail, industrial, etc.
Land Use Plan	A plan which establishes strategies for the use of land to meet identified community needs.
Land Wall	The concrete wall that forms part of the lock and is nearest to the land on the shore on which the lock chamber is constructed. (TNDOT1)
Landbridge	(See also Intermodal, Minibridge) An intermodal connection between two ocean carriers separated by a land mass, linked together in a seamless transaction by a land carrier. (MARAD1)
Landed Cost	The dollar per barrel price of crude oil at the port of discharge. Included are the charges associated with the purchase, transporting, and insuring of a cargo from the purchase point to the port of discharge. Not included are charges incurred at the discharge port (e.g., import tariffs or fees, wharfage charges, and demurrage charges). (DOE5)
Landed Weight	The weight of an aircraft providing scheduled and non-scheduled service of only property (including mail) in intrastate, interstate and foreign air transportation. (FAA11)
Landing Area	1) Any locality either on land, water, or structures, including airports/heliports and intermediate landing fields, which is used, or intended to be used, for the landing and takeoff of aircraft whether or not facilities are provided for the shelter, servicing, or for receiving or discharging passengers or cargo. 2) That part of a movement area intended for the landing or takeoff of aircraft. (FAA4)
Landing Direction Indicator	A device which visually indicates the direction in which landings and takeoffs should be made. (FAA4)
Landing Distance Available (LDA)	The runway length declared available for landing an airplane. (FAA12)
Landing Gear	Device that supports the front end of semitrailer when not attached to a tractor. (ATA1)
Landing Gear Extended Speed	The maximum speed at which an aircraft can be safely flown with the landing gear extended. (14CFR1)
Landing Gear Operating Speed	The maximum speed at which the landing gear can be safely extended or retracted. (14CFR1)
Landing Minimums	The minimum visibility prescribed for landing a civil aircraft while using an instrument approach procedure. The minimum applies with other limitations set forth in Federal Aviation Regulation Part 91 with respect to the Minimum Descent Altitude (MDA) or Decision Height (DH) prescribed in the instrument approach procedures as follows 1) Straight-in landing minimums. A statement of MDA and visibility, or DH and visibility, required for a straight-in landing on a specified runway, or 2) Circling minimums. A statement of MDA and visibility required for the circle-to-land maneuver. Descent below the established MDA or DH is not authorized during an approach unless the aircraft is in a position from which a normal approach to the runway of intended landing can be made and adequate visual reference to required visual cues is maintained. (FAA4)
Landing Place	A place for loading and unloading passengers or cargo to and from water vessels. (DOI4)
Landing Rights Airports	Any aircraft may land at one of these airports after securing prior permission to land from U.S. Customs. (FAA2)
Landing Roll	The distance from the point of touchdown to the point where the aircraft can be brought to a stop or exit the runway. (FAA4)
Landing Sequence	The order in which aircraft are positioned for landing. (FAA4)
Landing Signal	A prearranged signal which the towboats of some companies sound when approaching their dock. (TNDOT1)
Landscaping	(See also Brush Out) Colloquial term meaning to clear shore structure of brush and vegetation in order to obtain optimum range of visibility. (TNDOT1)
Lane	A portion of a street or highway, usually indicated by pavement markings, that is intended for one line of vehicles. (TRB1)
Large Air Carrier	Scheduled and nonscheduled aircraft operating under Federal Aviation Regulations (FAR) Parts 121, 125, or 127. Note Part 129 foreign air carriers are not included in the National Transportation Safety Board (NTSB) accident data base, nor are hour and departure data available for these air carriers. (FAA3)
Large Air Traffic Hub	A community enplaning 1.00 percent or more of the total enplaned passengers in all services and all operations for all communities within the 50 States, the District of Columbia, and other U.S. areas designated by the Federal Aviation Administration. (FAA2) (FAA14) (FAA15)
Large Aircraft	Aircraft of more than 12,500 pounds, maximum certificated takeoff weight. (14CFR1)
Large Aircraft Commercial Operator	Commercial operator operating aircraft of more than 12,500 pounds maximum certificated takeoff weight. (FAA9)
Large Certificated Air Carrier	An air carrier holding a Certificate of Public Convenience and Necessity that 1) operates aircraft designed to have a maximum passenger seating capacity of more than 60 seats or 2) maximum payload capacity of more than 18,000 pounds, (FAA2) (FAA11)
Large Certificated Air Carriers	An air carrier holding a certificate issued under section 401 of the Federal Aviation Act of 1958, as amended, that 1) operates aircraft designed to have a maximum passenger capacity of more than 60 seats or a maximum payload capacity of more than 18,000 pounds, or 2) conducts operations where one or both terminals of a flight stage are outside the 50 states of the United States, the District of Columbia, the Commonwealth of Puerto Rico, and the U.S. Virgin Islands. Large certificated air carriers are grouped by annual operating revenues 1) majors (more than $1 billion in annual operating revenues), 2) nationals (between $100 million and $1 billion in annual operating revenues), 3) large regionals (between $20 million and $99,999,999 in annual operating revenues), and 4) medium regionals (less than $20 million in annual operating revenues).
Large Fleet	A fleet of 2,000 or more reportable vehicles, domestic or foreign for which accountability is held by a department, independent establishment, bureau, or a comparable organizational unit of that department or independent establishment. (GSA1)
Large Regional Carrier Group	Air carrier groups with operating revenues between $20,000,000 and $99,000,000. (BTS4) (BTS5) (BTS6) (FAA11)
Large Regionals (Air)	Air carrier groups with annual operating revenues between $20 million and $99,999,999.
Large Truck	Trucks over 10,000 pounds gross vehicle weight rating, including single-unit trucks and truck tractors.
Lashing	A comparatively short manila line with an eye spliced in one end, used to moor barges and tows when passing through locks. Its average length is about 60 feet with sizes varying from 1 3/4 to 3 inches in circumference. The line is thrown somewhat in the manner of a lasso (hence the eye spliced) to catch a wall pin or bollard so as to snub the movement of barges and then moor them in the lock chamber. Also, any short length of line used to secure two barges end to end or side by side. (TNDOT1)
Last Assigned Altitude	The last altitude/flight level assigned by Air Traffic Control (ATC) and acknowledged by the pilot. (FAA4)
Latch Block	The lower extremity of a latch rod which engages with a square shoulder of the segment or quadrant to hold the lever in position. (49CFR236)
Latch Shoe	The casting by means of which the latch rod and the latch block are held to a lever of a mechanical interlocking machine. (49CFR236)
Lateral Dam	Usually a rock and brush structure constructed parallel with normal stream flow to train or confine the current to a definite channel. (TNDOT1)
Lateral Separation	The lateral spacing of aircraft at the same altitude by requiring operation on different routes or in different geographical locations. (FAA4)
Launching Ramp	A transportation structure used for launching boats. (DOI4)
Lay On the Air	Apply brakes. (ATA1)
Layover	Eight hours or more rest before continuing trip or any off-duty period away from home. (ATA1)
Lead Barge	The head, or first, barge of a tow generally with a rake. (TNDOT1)
Lead Wall	(See also Guide Wall) The long wall of a lock, also known as a "guided wall," outside the confines of the lock chamber, usually the land wall in the case of older locks. (TNDOT1)
Leaded Motor Gasoline	(See also Gasoline) Contains more than 0.05 grams of lead per gallon or more than 0.005 grams of phosphorus per gallon. The actual lead content of any given gallon may vary. Premium and regular grades are included, depending on the octane rating also leaded gasohol. Blendstock is excluded until blending has been completed. Alcohol that is to be used in the blending of gasohol is also excluded. (DOE5)
Lease	Acquisition of a vehicle by an agency from a commercial firm, in lieu of government ownership, for a period of 60 continuous days or more. (GSA1)
Lease Condensate	A mixture consisting primarily of pentanes and heavier hydrocarbons, which are recovered as a liquid from natural gas in lease or field separation facilities. This category excludes natural gas liquids, such as butane and propane, which are recovered at natural gas processing plants or facilities.
Leased Property (Under Capital Leases)	Total cost to the air carrier for all property obtained under leases that meet one or more of the following criteria; 1) The lease transfers ownership of the property to the lessee by the end of the lease term; 2) The lease contains a bargain purchase option; 3) The lease term is equal to 75 percent or more of the estimated economic life of the leased property; or 4) The present value at the beginning of the lease term of the minimum lease payments, excluding the portion of the payments representing executory costs such as insurance, maintenance and taxes to be paid by the lessor, including any profit thereon, equals or exceeds 90 percent of the excess of the fair value of the lease property to the lessor at the inception of the lease over any related investment tax credit retained by the lessor and expected to be realized by him. (BTS4)
Leasor	A person or firm that grants a lease. (MARAD1)
Left Bank	(See also Reflective Material, Right Bank) The left descending bank of a river. The side of the river marked by red buoys, white or red lights, and red reflective material. (TNDOT1)
Left-Hand Draft	Current which pulls tow to left. (TNDOT1)
Left-Hand Draft In This Set of Marks	Channel report term meaning that one should expect the tow to drift to the left while running this course. (TNDOT1)
Left-Hand Reef Makes Well In Toward Channel	Term indicating that an underwater sandbar is building in toward the channel. A condition requiring extra caution on the part of the pilot and possibly the need for a flanking maneuver if the channel is considerably constricted. (TNDOT1)
Legal Weight	The weight of the goods plus any immediate wrappings which are sold along with the goods, e.g., the weight of a tin can as well as its contents. (TNDOT1)
Less Than Containerload/Less Than Truckload (LCL/LTL)	A container or trailer loaded with cargo from more than one shipper; loads that do not by themselves meet the containerload or truckload requirements.
Less Than Truckload (LTL)	A quantity of freight less than that required for the application of a truckload rate. Usually less than 10,000 pounds and generally involves the use of terminal facilities to break and consolidate shipments. (ATA2)
Levee	(See also Lagoon, Lake) A built-up embankment on or back from the riverbank for the purpose of containing floodwater. (TNDOT1)
Level of Service (LOS)	1) A qualitative assessment of a road's operating conditions. For local government comprehensive planning purposes, level of service means an indicator of the extent or degree of service provided by, or proposed to be provided by, a facility based on and related to the operational characteristics of the facility. Level of service indicates the capacity per unit of demand for each public facility. 2) This term refers to a standard measurement used by transportation officials which reflects the relative ease of traffic flow on a scale of A to F, with free-flow being rated LOS-A and congested conditions rated as LOS-F.
License Plate Lamp	A lamp used to illuminate the license plate on the rear of a motor vehicle. (49CFR393)
Licensed Driver	Any person who holds a valid driver's license from any state. (FHWA3)
Lie Sheet	Driver's log book. (ATA1)
Lift on/Lift off cargo (LO/LO)	Containerized cargo that must be lifted on and off vessels and other vehicles using handling equipment.
Lift Vessel	A vessel designed to be loaded or unloaded by moving the containers with a heavy crane. (TNDOT1)
Light Boat	A towboat without a tow. (TNDOT1)
Light Density Railroad	Railroads with 1200 or less train-miles per road mile. (49CFR245)
Light Duty Vehicle	Automobiles and light trucks combined. (DOE6)
Light Gun	A handheld directional light signaling device which emits a brilliant narrow beam of white, green, or red light as selected by the tower controller. The color and type of light transmitted can be used to approve or disapprove anticipated pilot actions where radio communication is not available. The light gun is used for controlling traffic operating in the vicinity of the airport and on the airport movement area. (FAA4)
Light Rail	A streetcar-type vehicle operated on city streets, semi-exclusive rights-of-way, or exclusive rights-of-way. Service may be provided by step-entry vehicles or by level boarding.
Light Rail (StreetCar)	Urban transit which uses predominantly reserved but not always grade-separated rights-of-way. Electrically powered rail vehicles operate alone or in trains. (FTA2)
Light Rail Vehicles (Streetcars)	Rail cars with motive capability, usually driven by electric power taken from overhead lines, configured for passenger traffic and usually operating on non-exclusive right-of-way. (FTA)1
Light Stand	Colloquial term meaning the position or location of a shore-lighted aid to navigation. (TNDOT1)
Light Truck	Trucks of 10,000 pounds gross vehicle weight rating or less, including pickups, vans, truck-based station wagons, and sport utility vehicles.
Light-Duty Vehicle	A vehicle category that combines light automobiles and trucks.
Lighted Airport	An airport where runway and obstruction lighting is available. (FAA4)
Lighter	A barge used in off-loading an oceangoing vessel. (TNDOT1)
Lighter-Aboard-Ship (LASH)	A type of barge carrying vessel equipped with an overhead crane capable of lifting barges of a common size and stowing them into cellular slots in athwartship position. Lighter Aboard Ship (LAS) is an all-water technology analogous to containerization. (MARAD1)
Lighter-Than-Air Aircraft	Aircraft that can rise and remain suspended by using contained gas weighing less than the air that is displaced by the gas. (14CFR1)
Limitation on Obligations	Any action or inaction by an officer or employee of the United States that limits the amount of Federal assistance that may be obligated during a specified time period. A limitation on obligations does not affect the scheduled apportionment or allocation of funds, it just controls the rate at which these funds may be used.
Limited Maintenance Plan	A maintenance plan that EPA has determined meets EPA’s limited maintenance plan policy criteria for a given NAAQS and pollutant. To qualify for a limited maintenance plan, for example, an area must have a design value that is significantly below a given NAAQS, and it must be reasonable to expect that a NAAQS violation will not result from any level of future motor vehicle emissions growth.
Limited Radar Airport Traffic Control Tower	Airport traffic control tower at which air traffic control specialists are permitted to provide radar approach control service that requires only limited vectoring, as well as to handle takeoffs and landings. (FAA10) (FAA13)
Limousine or Auto Rental With Driver	Establishments primarily engaged in furnishing limousines or auto rentals with drivers, where such operations are principally within a single municipality, contiguous municipalities, or a municipality and its suburban areas eg. automobile rental with driver, limousine rental with driver, hearse rental with driver, passenger automobile rental with driver. (BOC1)
Line	One or more running tracks, each kilometre of line counting as one, however many tracks there may be. The total length of line operated is the length operated for passenger or goods transport, or both. Where a section of network comprises two or more lines running alongside on another, there are as many lines as routes to which tracks are allotted exclusively. (UN1)
Line Haul	The movement of freight over the road/rail from origin terminal to destination terminal, usually over long distances.
Line Miles	The sum of the actual physical length (measured in only one direction) of all streets, highways, or rights-of-way traversed by a transportation system (including exclusive rights-of-way and specially controlled facilities) regardless of the number of routes or vehicles that pass over any of the sections. (TRB1)
Line Section	A continuous run of pipe that is contained between adjacent pressure pump stations, between a pressure pump station and a terminal or breakout tank, between a pressure pump station and a block valve, or between adjacent block valves. (49CFR194) (49CFR195)
Line Spar	Line used to secure spar to deck. (TNDOT1)
Line Through	To pull boat through swift shallow channel by means of lines placed on bank. A term seldom used today. (TNDOT1)
Linear Referencing System (LRS) (LRS)	The total set of procedures for determining and retaining a record of specific points along a highway. Typical systems used are mile point, milepost, reference point, and link-node. (FHWA2)
Linear Service	International water carriers that ply fixed routes on published schedules. (MARAD1)
Linehaul	(See also Line-Haul) The movement of trains between terminals and stations on the main or branch lines of the road, exclusive of switching movements. (AAR1)
Line-Haul	(See also Linehaul) Transportation from one city to another as differentiated from local switching service. (MARAD2)
Line-Haul Operation Railroads	Establishments primarily engaged in line-haul railroad passenger and freight operations. (BOC1)
Liner	A vessel sailing between specified ports on a regular basis. (MARAD2)
Liner Terms	An expression covering assessment of ocean freight rates generally implying that loading and discharging expenses will be for ship owner's account, and usually apply from the end of ship's tackle in port of loading to the end of ship's tackle in port of discharge. (TNDOT1)
Lines (Used In Towing)	Back line, backing line, breast line, check line, dropping out line, face line, fore and aft line, handy line, head line, jockey line, lashing, lead line, lock line, monkey line, quarter line, side line, spar line, stem line, tow line, spring line, peg line. (TNDOT1)
Linked Passenger Trip	A trip from origin to destination on the transit system. Even if a passenger must make several transfers during a journey, the trip is counted as one linked trip on the system. (FTA1)
Liquefied Natural Gas (LNG)	Natural gas, primarily methane, that has been liquefied by reducing its temperature to –260 °F at atmospheric pressure.
Liquefied Natural Gas (LNG) Facility (LNG)	A pipeline facility that is used for liquefying or solidifying natural gas or synthetic gas or transferring, storing, or vaporizing liquefied natural gas. (49CFR193)
Liquefied Petroleum Gas (LPG)	Pro-pane, propylene, normal butane, butylene, isobutane, and isobutylene produced at refineries or natural gas processing plants, including plants that fractionate new natural gas plant liquids.
Liquefied Petroleum Gases (LPG) (LPG)	Ethane, ethylene, propane, propylene, normal butane, butylene, and isobutane produced at refineries or natural gas processing plants, including plants that fractionate new natural gas plant liquids. (DOE3)
Liquid	A material that has a vertical flow of over 2 inches (50 mm) within a three minute period, or a material having one gram or more liquid separation, when determined in accordance with the procedures specified in American Society for Testing and Materials (ASTM) specification D4359-84, "Standard Test Method for Determining whether a Material is a Liquid or Solid," 1984 edition. (49CFR171)
Liquid Bulk Cargo	A type of bulk cargo that consists of liquid items, such as petroleum, water, or liquid natural gas.
Liquid Petroleum Gas (LPG) (LPG)	Consists of propane and butane and is usually derived from natural gas. In locations where there is no natural gas and the gasoline consumption is low, naphtha is converted to LPG by catalytic reforming. (AGA1) (DOE6)
Liquid Phase	A material that meets the definition of liquid when evaluated at the higher of the temperature at which it is offered for transportation or at which it is transported, not at the 37.8 degree C (100 degree F) temperature specified in American Society for Testing and Materials (ASTM) specification D4359-84. (49CFR171)
Lite Locomotive	A locomotive or a consist of locomotives not attached to any piece of equipment or attached only to a caboose. (49CFR229)
Lives Lost	Those persons who perished as a direct result of the distress incident to which the Coast Guard was responding. Lives Lost Before refers to those persons who were considered lost prior to Coast Guard notification. Lives Lost After refers to those persons who were alive at the time of Coast Guard notification, but who subsequently died. (USCG3)
Lives Saved	Those persons who would have been lost without Coast Guard assistance. (USCG3)
Livestock Body	Truck or trailer designed for the transportation of farm animals. (ATA1)
Load Factor	A term relating the potential capacity of a system relative to its actual performance. Is often calculated as total passenger miles divided by total vehicle miles. (DOE6)
Load Ratio	The ratio of loaded miles to empty miles per tractor. (MARAD2)
Loaded Car Mile	A loaded car mile is a mile run by a freight car with a load. In the case of intermodal movements, the car miles generated will be loaded or empty depending on whether the trailers/containers are moved with or without a waybill, respectively. (AAR1)
Loading Island	1) A pedestrian refuge within the right-of-way and traffic lanes of a highway or street. It is provided at designated transit stops for the protection of passengers from traffic while they wait for and board or alight from transit vehicles. 2) A protected spot for the loading and unloading of passengers. (TRB1)
Loading Tramway	A pair of rails running down the riverbank upon which a cart rides for the purpose of loading buoys and other equipment aboard a tender. (TNDOT1)
Local Aircraft Operations	Performed by aircraft that 1) Operate in the local traffic pattern or within sight of the airport; 2) Known to be departing for, or arriving from flight in local practice areas located within a 20-mile radius of the airport; 3) Execute simulated instrument approaches or low passes at the airport. (FAA13) (FAA14)
Local Airport Advisory (LAA) (LAA)	A service provided by flight service stations or the military at airports not serviced by an operating control tower. This service consists of providing information to arriving and departing aircraft concerning wind direction and speed, favored runway, altimeter setting, pertinent known traffic, pertinent known field conditions, airport taxi routes and traffic patterns, and authorized instrument approach procedures. This information is advisory in nature and does not constitute an Air Traffic Control (ATC) clearance. (FAA4)
Local and Suburban and Interurban Passenger Transportation Transit	Includes establishments that provide local and suburban passenger transportation, such as those providing passenger transportation within a single municipality, contiguous municipalities, or a municipality and its suburban areas by bus, rail, car subway, either separately or in combination. Also included are sightseeing, charter, intercity passenger operations, and establishments providing passenger terminal and maintenance facilities. (BEA1)
Local and Suburban Transit	Establishments primarily engaged in furnishing local and suburban mass passenger transportation over regular routes and on regular schedules, with operations confined principally to a municipality, contiguous municipalities, or a municipality and its suburban areas. Also included in this industry are establishments primarily engaged in furnishing passenger transportation by automobile, bus, or rail to, from, or between airports or rail terminals over regular routes and those providing bus and rail commuter services. (BOC1)
Local Bus Charter Service	Establishments primarily engaged in furnishing local bus charter service where such operations are principally within a single municipality, contiguous municipalities or a municipality and its suburban areas. (BOC1)
Local Courier Service	Establishments primarily engaged in the delivery of individually addressed letters, parcels, or packages (generally under 100 pounds), except by means of air transportation or by the United States Postal Service. Delivery is usually made by street or highway within a local area or between cities. (BOC1)
Local Freight	Freight movements within the confines of a port, whether the port has only one or several arms or channels (except car ferry and general ferry). The term is also applied to marine products, sand, and gravel taken directly from the Great Lakes. (TNDOT1)
Local Operations	Performed by aircraft which; 1) Operate in the local traffic pattern or within sight of the airport. 2) Are known to be departing for, or arriving from, flight in local practice areas within a 20 mile radius of the airport. 3) Execute simulated instrument approaches or low passes at the airport. Itinerant operations are all airport operations other than local operations. (FAA2)
Local Passenger (Not Elsewhere Classified) Transportation	Establishments primarily engaged in furnishing miscellaneous passenger transportation, where such operations are principally within a single municipality, contiguous municipalities, or a municipality and its suburban areas. (BOC1)
Local Roads	Those roads and streets whose principal function is to provide direct access to abutting land. (FHWA5)
Local Street	A street intended solely for access to adjacent properties.
Local Streets and Roads	(See also Highway, Road) Streets whose primary purpose is feeding higher order systems, providing direct access with little or no through traffic. (NHTSA3)
Local Technical Assistance Program Center	These Centers are responsible for providing transportation assistance to State and local governments that includes, but is not limited to, circuit rider programs, providing training on intergovernmental transportation planning and project selection, and tourism recreation travel.
Local Traffic	1) Aircraft operating in the traffic pattern or within sight of the tower. 2) Aircraft known to be departing or arriving from flight in local practice areas. 3) Aircraft executing practice instrument approaches at the airport. (FAA4)
Local Trip	An intracity or short mileage trip by commercial motor vehicle. (FHWA4)
Local Trucking (With Storage)	Establishments primarily engaged in furnishing both trucking and storage services, including household goods, within a single municipality, contiguous municipalities, or a municipality and its suburban areas. (BOC1)
Local Trucking (Without Storage)	Establishments primarily engaged in furnishing trucking or transfer services without storage for freight generally weighing more than 100 pounds, in a single municipality, contiguous municipalities, or a municipality and its suburban areas. (BOC1)
Localizer	(See also Glideslope, Instrument Landing System, Middle Marker, Outer Marker) The component of an Instrument Landing System (ILS) which provides course guidance to the runway. (FAA4)
Localizer Course	The locus of points, in any given horizontal plane, at which the difference in depth of modulation (DDM) is zero. (FAA4)
Localizer Type Directional Aid	A Navigational Aid (NAVAID) used for nonprecision instrument approaches with utility and accuracy comparable to a localizer but which is not a part of a complete Instrument Landing System and is not aligned with the runway. (FAA4)
Localizer Usable Distance	The maximum distance from the localizer transmitter at a specified altitude, as verified by flight inspection, at which reliable course information is continuously received. (FAA4)
Location Identifier (LOCID)	A unique code which is assigned by the Federal Aviation Administration (FAA) to identify each airport. (FAA11)
Locator	A low/medium frequency (LM/MF) nondirectional beacon (NDB) used as an aid to final approach. Note A locator usually has an average radius of rated coverage of between 18.6 and 46.3 miles (10 and 26 NM). (FAA4)
Lock	A channel where the water rises and falls to allow boats to travel a dammed river.
Lock Cell	The chamber of a lock. (TNDOT1)
Lock Gate	A movable, structural barrier to hold back the water in a lock chamber. (TNDOT1)
Lock Line	A long line led from the bow and the stern of the tow to the lock wall. (TNDOT1)
Lock Rod	[with respect to rail operations] A rod, attached to the front rod or lug of a switch, movable-point frog or derail, through which a locking plunger may extend when the switch points or derail are in the normal or reverse position. (49CFR236)
Lock Traffic Lights	Red, yellow, and green lights displayed at the entrances of the lock, both up bound and down bound, for the purpose of controlling traffic. (TNDOT1)
Locking Bar	[with respect to rail operations] A bar in an interlocking machine to which the locking dogs are attached. (49CFR236)
Locking Bed	[with respect to rail operations] That part of an interlocking machine that contains or holds the tappets, locking bars, crosslocking, dogs and other apparatus used to interlock the levers. (49CFR236)
Locking Dog	(See also Dog Chart) [with respect to rail operations] A steel block attached to a locking bar or tappet of an interlocking machine, by means of which locking between levers is accomplished. (49CFR236)
Locking Face	[with respect to rail operations] The locking surface of a locking dog, tappet or cross locking of an interlocking machine. (49CFR236)
Locking Sheet	A description in tabular form of the locking operations in an interlocking machine. (49CFR236)
Locking Time	The total time required for a tow to pass through a locking procedure. This includes approach time, chamber time, and time to clear the lock. (TNDOT1)
Locomotive	Railroad vehicle equipped with flanged wheels for use on railroad tracks, powered directly by electricity, steam, or fossil fuel, and used to move other railroad rolling equipment.
Locomotive Cab	That portion of the superstructure designed to be occupied by the crew while operating the locomotive. (49CFR223)
Locomotive Mile	The movement of a locomotive under its own power the distance of one mile. (FRA3)
Locomotive Unit Mile	The movement of a locomotive unit one mile under its own power. Miles of locomotives in helper service are computed on the basis of actual distance run in such service. Locomotive unit miles in road service are based on the actual distance run between terminals and/or stations. Train switching locomotive unit miles are computed at the rate of six miles per hour for the time actually engaged in such service. (AAR1)
Locomotive-Mile	The movement of a locomotive unit, under its own power, the distance of 1 mile.
Log Body	Truck or trailer designed for the transportation of logs or other loads which may be boomed or chained in place. (ATA1)
Logistics	All activities involved in the management of product movement; delivering the right product from the right origin to the right destination, with the right quality and quantity, at the right schedule and price.
Long Range Navigation (LRNAV)	A method of navigation that permits navigation over long distances. This is in contrast to the relatively short range navigation provided by the Very High Frequency Omni-Directional Radio Range (VOR) system. (FAA6) (FAA10)
Long Range Transportation Plan (LRTP)	A document resulting from regional or statewide collaboration and consensus on a region or state's transportation system, and serving as the defining vision for the region's or state's transportation systems and services. In metropolitan areas, the plan indicates all of the transportation improvements scheduled for funding over the next 20 years.
Long Term	In transportation planning, refers to a time span of, generally, 20 years. The transportation plan for metropolitan areas and for States should include projections for land use, population, and employment for the 20-year period.
Long Ton	2,240 pounds. (MARAD2)
Longer Combination Vehicles (LCV)	Any combination of truck tractor and two or more trailers or semitrailers which operates on the Interstate System at a gross vehicle weight greater than 80,000 pounds. (23CFR658)
Longitudinal	Parallel to the longitudinal centerline of the vehicle. (49CFR571)
Longitudinal Separation	The longitudinal spacing of aircraft at the same altitude by a minimum distance expressed in units of time or miles. (FAA4)
Loose-Headed	Light board under way. (TNDOT1)
Loran	An electronic navigational system by which hyperbolic lines of position are determined by measuring the difference in the time of reception of synchronized pulse signals from two fixed transmitters. Loran A operates in the 1750-1950 kHz frequency band. Loran C and D operate in the 100-110 kHz frequency band. (FAA4)
Lost Communications	Loss of the ability to communicate by radio. Aircraft are sometimes referred to as NORDO (No Radio). Standard pilot procedures are specified in Federal Aviation Regulation (FAR) Part 91. Radar controllers issue procedures for pilots to follow in the event of lost communications during a radar approach when weather reports indicate that an aircraft will likely encounter Instrument Flight Rules (IFR) weather conditions during the approach. (FAA4)
Lost Workdays	Any full day or part of a day (consecutive or not) other than the day of injury, that a railroad employee is away from work because of injury or occupational illness. (49CFR225)
Low Altitude Airway Structure (LAAS)	The network of airways serving aircraft operations up to but not including 18,000 feet mean sea level (MSL). (FAA4)
Low Altitude Alert System (LAAS)	An automated function of the TPX42 that alerts the controller when a Mode C transponder equipped aircraft on an Instrument Flight Rules (IFR) flight plan is below a predetermined minimum safe altitude. If requested by the pilot, Low Altitude Alert System (LAAS) monitoring is also available to Visual Flight Rules (VFR) Mode C transponder equipped aircraft. (FAA4)
Low Approach	An approach over an airport or runway following an instrument approach or a Visual Flight Rules (VFR) approach including the go-around maneuver where the pilot intentionally does not make contact with the runway. (FAA4)
Low Boy	A low trailer for hauling heavy machinery. (ATA1)
Low Emission Vehicle	A clean fuel vehicle meeting the low-emission vehicle standards. (DOE6)
Low Frequency	The frequency band between 30 and 300 kHz. (FAA4)
Low Head	Vertical difference of 100 feet or less in the upstream surface water elevation (headwater) and the downstream surface water elevation (tailwater) at a dam. (DOE5)
Low Impact Resistant Supports (LIRS)	Supports designed to resist operational and environmental static loads and fail when subjected to a shock load such as that from a colliding aircraft. (FAA12)
Low Type Road Surface	Bituminous surface-treated Surface/Pavement Type Code 51. (FHWA2)
Low Water Dam	(See also Weir) 1) A low level dam designed to hold back a head of water so as to maintain project depth in a certain area. The dam may be visible at the low water stage. 2) A dam that is more effective at low water; at high water the dam becomes a weir. (TNDOT1)
Low Water Datum	A term used by the Corps of Engineers to define their originating point of elevation in determining stages of water when erecting various gages along the river. (TNDOT1)
Lower Gage	A gage located in the tailwater of a dam (downstream side); colloquially called "tailgate". (TNDOT1)
Lower-Half of Saddle-Mount	(See also King-Pin Saddle-Mount, Saddle-Mount, Upper-Half of Saddle-Mount) That part of the device which is securely attached to the towing vehicle and maintains a fixed position relative thereto but does not include the "king-pin." (49CFR393)
Lumber Body	Platform truck or trailer body with traverse rollers designed for the transportation of sawed lumber. (ATA1)
Mach Number	The ratio of true airspeed to the speed of sound. (14CFR1) (FAA4)
Mach Technique	Describes a control technique used by air traffic control whereby turbojet aircraft operating successively along suitable routes are cleared to maintain appropriate MACH numbers for a relevant portion of the en route phase of flight. The principle objective is to achieve improved utilization of the airspace and to ensure that separation between successive aircraft does not decrease below the established minima. (FAA4)
Mackinaw Boat	A crudely built flatboat used on the Ohio and Upper Mississippi rivers during the 18th century. (TNDOT1)
Magazine Vessel	A vessel used for the receiving, storing, or dispensing of explosives. (49CFR171)
Magnetic Levitation	A rail transportation system with exclusive right-of-way which is propelled along a fixed guideway system by the attraction or repulsion of magnets on the rails and under the rail cars. (APTA1)
Mail Revenue	Revenues from the carriage of mail bearing postage for air transportation both U.S. and foreign mail that go by air on priority and nonpriority bases. (BTS4)
Main	A distribution line that serves as a common source of supply for more than one gas service line. (AGA1)
Main Deck	The lowest deck on a river steamboat. The main deck supports the vessel's engines and boilers and has space for fuel and cargo. (TNDOT1)
Main Heating Fuel	Fuel that powers the main heating equipment. (DOE5)
Main Rotor	The rotor that supplies the principal lift to a rotorcraft. (14CFR1)
Main Stem	The main portion of navigable channel of a river where more than one channel exists. (TNDOT1)
Main Track	A track, other than an auxiliary track, extending through yards or between stations, upon which trains are operated by timetable or train order or both, or the use of which is governed by a signal system. (49CFR218) (49CFR221) (49CFR236) (49CFR245) (FRA3)
Mains (Gas)	A network of pipelines that serves as a common source of supply for more than one gas service line.
Maintain	1) Concerning altitude flight level, the term means to remain at the altitude flight level specified. The phrase "climb and" or "descend and" normally precedes "maintain" and the altitude assignment; e.g., "descend and maintain 5,000". 2) Concerning other Air Traffic Control (ATC) instructions, the term is used in its literal sense; (e.g., maintain Visual Flight Rule (VFR)). (FAA4)
Maintenance	(See also Preventive Maintenance) Inspection, overhaul, repair, preservation, and the replacement of parts, but excludes preventive maintenance. (14CFR1)
Maintenance Area	Maintenance area is any geographic region of the United States previously designated nonattainment pursuant to the CAA Amendments of 1990 and subsequently redesignated to attainment subject to the requirement to develop a maintenance plan under section 175A of the CAA, as amended.
Maintenance Control Center (MCC)	(See also Preventive Maintenance) Responsible for the oversight of authorization for vehicle repair and authorization and certification of maintenance and repair invoices for Interagency Fleet Management System (IFMS) vehicles within the specified region(s). The MCC also contacts vendors to schedule vehicle services. (GSA2)
Major Alteration	An alteration not listed in the aircraft, aircraft engine, or propeller specifications that 1) Might appreciably affect weight, balance, structural strength, performance, powerplant operation, flight characteristics, or other qualities affecting airworthiness; or 2) Done according to accepted practices cannot be done by elementary operations. (14CFR1)
Major Carrier Group	Air carrier groups with annual operating revenues exceeding $1,000,000,000. (BTS4) (BTS5) (BTS6) (FAA11)
Major Fuel	Fuels or energy sources such as electricity, fuel oil, liquefied petroleum gases, natural gas, district steam, district hot water, and district chilled water. (DOE5)
Major Interstate Pipeline Company	A company whose combined sales for resale, including gas transported interstate or stored for a fee, exceeded 50 million thousand cubic feet in the previous year. (DOE5)
Major Repair	A repair that, if improperly done, might appreciably affect weight, balance, structural strength, performance, powerplant operation, flight characteristics, or other qualities affecting airworthiness; or that is not done according to accepted practices or cannot be done by elementary operations. (14CFR1)
Major River	A river that, because of its velocity and vessel traffic, would require a more rapid response in case of a worst case discharge. (49CFR194)
Majors (Air)	Air carrier groups with annual operating revenues exceeding $1 billion.
Make Short Approach	Used by Air Traffic Control (ATC) to inform a pilot to alter his traffic pattern 80 degrees as to make a short final approach. (FAA4)
Make Up Tow	To assemble barges into a tow. (TNDOT1)
Management Systems	(1) Systems to improve identification of problems and opportunities throughout the entire surface transportation network, and to evaluate and prioritize alternative strategies, actions and solutions. (2) A systematic process, designed to assist decisionmakers in selecting cost-effective strategies/actions to improve the efficiency and safety of, and protect the investment in, the nation's transportation infrastructure.
Mandatory Altitude	An altitude depicted on an instrument approach procedure chart requiring the aircraft to maintain altitude at the depicted value. (FAA4)
Mandatory Use Seat Belt Law	(See also Manual Restraint System, Restraint Usage) A law requiring some adult occupants of some traffic vehicles to use available restraint systems. (NHTSA1)
Maneuver Boat	Boat used by the Corps of Engineers in raising and lowering movable wickets of dams on the Ohio River. (TNDOT1)
Maneuvering	Changing of course, speed, or similar boat handling action during which a high degree of alertness is required or the boat is imperiled because of the operation, i.e. docking, mooring, undocking, etc. (USCG2)
Man-Hour	An industrial unit of production reflecting paid labor hours. (FRA3)
Maniac	Shop mechanic. (ATA1)
Manifold Pressure	Absolute pressure as measured at the appropriate point in the induction system and usually expressed in inches of mercury. (14CFR1)
Manner of Collision	A classification for crashes in which the first harmful event was a collision between two motor vehicles in transport. (NHTSA3)
Manual Interlocking	An arrangement of signals and signal appliances operated from an interlocking machine and so interconnected by means of mechanical and/or electric locking that their movements must succeed each other in proper sequence, train movements over all routes being governed by signal indication. (49CFR236)
Manual Restraint System	(See also Mandatory Use Seat Belt Law, Restraint Usage) Occupant restraints that require some action, usually buckling, before they are effective. They include shoulder belt, lap belt, lap and shoulder belt, infant carrier, or child safety seat. (NHTSA1)
Manufacturer	1) Any person engaged in the manufacture, construction, or assembly of boats or associated equipment 2) The manufacture or construction of components for boats and associated 3) Equipment to be sold for subsequent assembly or 4) The importation into the United States for sale of boats, associated equipment, or components thereof. (USCG1)
Manufacturer Identification Code (MIC)	Three-character identifier assigned by Headquarters on request to those manufacturers and importers defined under 33 CFR 181.31. (USCG1)
Marina	(See also Dock, Pier, Harbor, Wharf) Establishments primarily engaged in operating marinas. These establishments rent boat slips and store boats, and generally perform a range of other services including cleaning and incidental boat repair. They frequently sell food, fuel, and fishing supplies, and may sell boats. (BOC1)
Marine Cargo Handling	Establishments primarily engaged in activities directly related to marine cargo handling from the time cargo, for or from a vessel, arrives at shipside, dock, pier, terminal, staging area, or in-transit area until cargo loading or unloading operations are completed. Included in this industry are establishments primarily engaged in the transfer of cargo between ship and barges, trucks, trains, pipelines, and wharfs. Cargo handling operations carried on by transportation companies and separately reported are classified here. This industry includes the operation and maintenance of piers, docks, and associated buildings and facilities. (BOC1)
Marine Pollutant	(See also Hazardous Material) A hazardous material which is listed in Appendix B to CFR 172.101 of this subchapter and, when in a solution or mixture of one or more marine pollutants, is packaged in a concentration which equals or exceeds 1) Ten percent by weight of the solution or mixture for materials listed in the appendix; or 2) One percent by weight of the solution or mixture for materials that are identified as severe marine pollutants in the appendix. (49CFR171)
Marine Sanitation Device (MSD)	Any equipment for installation on board a vessel which is designed to receive, retrain, treat or discharge sewage and any process to treat such sewage. (USCG1)
Marine Terminal	A designated area of a port, which includes but not limited to wharves, warehouses, covered and/or open storage spaces, cold storage plants, grain elevators and/or bulk cargo loading and/or unloading structures, landings, and receiving stations, used for the transmission, care, and convenience of cargo and/or passengers in the interchange of same between land and water carriers or between two water carriers. (MARAD1)
Marine Terminal Operator	Person or entity that operates the various marine terminals at ports, usually under long-term lease agreements with local or state governments or port authorities. The marine terminal operator provides receiving and delivery, and other terminal services for the cargos moving through these facilities. (MARAD1)
Maritime	Business pertaining to commerce or navigation transacted upon the sea or in seaports in such matters as the court of admiralty has jurisdiction. (MARAD2)
Maritime Administration (MARAD)	The Maritime Administration was established by Reorganization Plan No. 21 of 1950 (5 U.S.C. app.) effective May 24, 1950. The Maritime Act of 1981 (46 U.S.C. 1601) transferred the Maritime Administration to the Department of Transportation, effective Aug
Maritime Carrier	Carriers which operate on the open sea, i.e., their operations must include a foreign or international component and may include a domestic component. (TNDOT1)
Maritime Revenue	Revenue received for operations in international or foreign shipping. (TNDOT1)
Mark Twain	Colloquial term for 12-foot depth or mark 2 on the lead line. (TNDOT1)
Marked Channel	Channel marked by buoys. (TNDOT1)
Marker Beacon	An electronic navigation facility transmitting a 76 mHz vertical fan or boneshaped radiation pattern. Marker beacons are identified by their modulation frequency and keying code, and when received by compatible airborne equipment, indicate to the pilot, both aurally and visually, that he is passing over the facility. (FAA4)
Marketed Production	Gross withdrawals less gas used for repressuring, quantities vented and flared, and nonhydrocarbon gases removed in treating or processing operations. Includes all quantities of gas used in field and processing operations. (DOE3)
Marking	A descriptive name, identification number, instructions, cautions, weight, specification, or combinations thereof, required by this subchapter on outer packagings of hazardous materials. (49CFR171)
Mass Transit	Another name for public transportation. (APTA1)
Mass Transportation	Another name for public transportation. (APTA1)
Mass Transportation Agency	An agency authorized to transport people by bus, rail, or other conveyance, either publicly or privately owned, and providing to the public general or special service (but not including school, charter or sightseeing service) on a regular basis. (FTA1)
Material Handling	Short-distance movement of goods within a storage area. (MARAD1)
Material Handling Equipment	Forklift trucks, platform trucks, warehousing industrial cranes, straddle carrier trucks, pallet trucks, platform trucks, warehousing trailers, conveyer systems, and others, used in storage and handling operations. (MARAD1)
Maxi-Cube Vehicle	A combination vehicle consisting of a power unit and a trailing unit, both of which are designed to carry cargo. The power unit is a nonarticulated truck with one or more drive axles that carries either a detachable or a permanently attached cargo box. The trailing unit is a trailer or semitrailer with a cargo box so designed that the power unit may be loaded and unloaded through the trailing unit. (23CFR658)
Maximum Extent Practicable	The limits of available technology and the practical and technical limits on a pipeline operator in planning the response resources required to provide the on-water recovery capability and the shoreline protection and cleanup capability to conduct response activities for a worst case discharge from a pipeline in adverse weather. (49CFR194)
Maximum High Water Elevation	The highest water level reached during the past 200 years of record keeping. (TNDOT1)
May Day	(See also Pan Pan) The international radiotelephony distress signal. When repeated three times, it indicates imminent and grave danger and that immediate assistance is requested. (FAA4)
Mean	(See also Estimate Ratio; Ratio Estimate) The simple arithmetic average for a population; that is, the sum of all the values in a population divided by the size of the population. For this report, population means are estimated by computing the weighted sum of the sample values, then dividing by the sum of the sample weights. The mean is, thus, an aggregate ratio whose denominator is the total number of households or vehicles. (DOE4)
Means of Transportation	(See also Mode) A mode used for going from one place (origin) to another (destination). Includes private and public modes, as well as walking. For all travel day trips, each change of mode constitutes a separate trip. (FHWA3)
Measurement Ton	40 cubic feet. (MARAD2)
Measures of Effectiveness	Measures or tests which reflect the degree of attainment of particular objectives.
Median Category	Inclusion of a median within single instance of road. (DOI3)
Median Included	Median is included within the instance of road. (DOI3)
Median Not Included	Median is not included because there is no median or median is wide enough to cause separate instances of road. (DOI3)
Medium Air Traffic Hub	A community enplaning from 0.25 to 0.99 percent of the total enplaned passengers in all services and all operations for all communities within the 50 States, the District of Columbia, and other U.S. areas designated by the Federal Aviation Administration. (FAA2) (FAA14) (FAA15)
Medium or Heavy Trucks	A motor vehicle with a Gross Vehicle Weight Rating (GVWR) greater than 10,000 pounds (buses, motorhomes, and farm and construction equipment other than trucks are excluded). (NHTSA4)
Medium Regional Carrier Group	Carrier groups with annual operating revenues less than $19,999,999 or that operate only aircraft with 60 seats or less (or 18,000 lbs maximum payload). (BTS4) (BTS5) (BTS6) (FAA11)
Medium Regionals (Air)	Air carrier groups with annual operating revenues less than $20 million.
Medium Size Bus	A bus from 29 to 34 feet in length. (APTA1)
Medium Speed	A speed not exceeding 40 miles per hour. (49CFR236)
Megawatt	See also Electricity, Gigawatt, Kilowatt.
Megawatt Electric (MWE)	One million watts of electric capacity. (DOE5)
Memorandum of Understanding (MOU)	A document providing a general description of the responsibilities that are to be assumed by two or more parties in their pursuit of some goal(s). More specific information may be provided in an associated SOW.
Merchandise Trade Exports	Merchandise transported out of the United States to foreign countries whether such merchandise is exported from within the U.S. Customs Service territory, from a U.S. Customs bonded warehouse, or from a U.S. Foreign Trade Zone. (Foreign Trade Zones are areas, operated as public utilities, under the control of U.S. Customs with facilities for handling, storing, manipulating, manufacturing, and exhibiting goods.)
Merchandise Trade Imports	Com-modities of foreign origin entering the United States, as well as goods of domestic origin returned to the United States with no change in condition or after having been processed and/or assembled in other countries. Puerto Rico is a Customs district within the U.S. Customs territory, and its trade with foreign countries is included in U.S. import statistics. U.S. import statistics also include merchandise trade between the U. S. Virgin Islands and foreign countries even though the Islands are not officially a part of the U.S. Customs territory.
Meteorological Impact Statement	An unscheduled planning forecast describing conditions expected to begin within 4 to 12 hours which may impact the flow of air traffic in a specific Air Route Traffic Control Center's (ARTCC) area. (FAA4)
Meter Fix/Slot Time	A calculated time to depart the meter fix in order to cross the vertex at the Actual Calculated Landing Time (ACLT). This time reflects descent speed adjustment and any applicable time that must be absorbed prior to crossing the meter fix. (FAA4)
Metered Data	End-use data obtained through the direct measurement of the total energy consumed for specific uses within the individual household. Individual appliances can be submetered by connecting the recording meters directly to individual appliances. (DOE5)
Metering	A method of time regulating arrival traffic flow into a terminal area so as not to exceed a predetermined terminal acceptance rate. (FAA4)
Metering Airports	Airports adapted for metering and for which optimum flight paths are defined. A maximum of 16 airports may be adapted. (FAA4)
Metering Fix	A fix along an established route from over which aircraft will be metered prior to entering terminal airspace. Normally, this fix should be established at a distance from the airport which will facilitate a profile descent 10,000 feet above airport elevation or above. (FAA4)
Methanol	A light, volatile alcohol produced commercially by the catalyzed reaction of hydrogen and carbon monoxide. Methanol is blended with gasoline to improve its operational efficiency.
Methyl-Tertiary-Butyl-Ether (MTBE)	A colorless, flammable, liquid oxygenated hydrocarbon that contains 18.15 percent oxygen. It is a fuel oxygenate produced by reacting methanol with isobutylene.
Metric	Refers to the modernized metric system known as the International System. (FHWA2)
Metric Ton	A unit of weight equal to 2,204.6 pounds. (DOE5)
Metropolitan Planning Area	The geographic area in which the metropolitan transportation planning process required by 23 U.S.C. 134 and section 8 of the Federal Transit Act (49 U.S.C. app. 1607) must be carried out. (23CFR420)
Metropolitan Planning Organization (MPO)	1) Regional policy body, required in urbanized areas with populations over 50,000, and designated by local officials and the governor of the state. Responsible in cooperation with the state and other transportation providers for carrying out the metropolitan transportation planning requirements of federal highway and transit legislation. 2) Formed in cooperation with the state, develops transportation plans and programs for the metropolitan area. For each urbanized area, a Metropolitan Planning Organization (MPO) must be designated by agreement between the Governor and local units of government representing 75% of the affected population (in the metropolitan area), including the central cities or cities as defined by the Bureau of the Census, or in accordance with procedures established by applicable State or local law (23 U.S.C. 134(b)(1)/Federal Transit Act of 1991 Sec. 8(b)(1)). (FHWA2)
Metropolitan Railway	Another name for "Heavy Rail." (APTA1)
Metropolitan Statistical Area (MSA)	Areas defined by the U.S. Office of Management and Budget. A Metropolitan Statistical Area (MSA) is 1) A county or a group of contiguous counties that contain at least one city of 50,000 inhabitants or more, or 2) An urbanized area of at least 50,000 inhabitants and a total MSA population of at least 100,000 (75,000 in New England). The contiguous counties are included in an MSA if, according to certain criteria, they are essentially metropolitan in character and are socially and economically integrated with the central city. In New England, MSAs consist of towns and cities rather than counties. (DOE4) (DOE5) (FHWA3)
Metropolitan Status	A building classification referring to the location of the building either located within a Metropolitan Statistical Area (MSA) or outside a MSA. (DOE5)
Metropolitan Transportation Plan (MTP)	The official intermodal transportation plan that is developed and adopted through the metropolitan transportation planning process for the metropolitan planning area, in accordance with 23 U.S.C. 134, 23 USC 135 and 49 U.S.C. 5303.
Mexican Overdrive	Kicking out of gear going down grade. (ATA1)
Microbridge	A cargo movement in which the water carrier provides a through service between an inland point and the port of load/discharge. (MARAD2)
Microburst	A small downburst with outbursts of damaging winds extending 2.5 miles or less. In spite of its small horizontal scale, an intense microburst could induce wind speeds as high as 150 knots. (FAA4)
Microwave Landing System (MLS)	A precision instrument approach system operating in the microwave spectrum which normally consists of the following components 1) Azimuth Station. 2) Elevation Station. 3) Precision Distance Measuring Equipment. (FAA4)
Midday Period	The period between the end of the A.M. peak and the beginning of the P.M. peak. (FTA1)
Middle Bar	Bar in middle of river. (TNDOT1)
Middle Compass Locator (MCL)	A compass locator installed at the site of the middle marker of an instrument landing system. (FAA4)
Middle Marker (MM)	(See also Compass Locator, Glideslope, Instrument Landing System, Localizer, Outer Marker) A marker beacon that defines a point along the glideslope of an Instrument Landing System (ILS) normally located at or near the point of decision height (ILS Category I). It is keyed to transmit alternate dots and dashes, with the alternate dots and dashes keyed at the rate of 95 dot/dash combinations per minute on a 1300 Hz tone, which is received aurally and visually by compatible airborne equipment. (FAA4)
Midgrade Unleaded Gasoline	(See also Fuel, Gasohol, Gasoline, Kerosene) Gasoline having an antiknock index (R+M/2) greater than or equal to 88, or less than or equal to 90, and containing not more than 0.05 grams of lead or 0.005 grams of phosphorus per gallon. (DOE5)
Mile	A statute mile (5,280 feet). All mileage computations are based on statute miles. (BTS5) (BTS6)
Mile Board	A 12 by 36 inch board mounted horizontally above a shore to aid in navigation and labeled with the river mileage at that point. (TNDOT1)
Mile Marker	A point on a feature indicating the distance, in miles, measured along the course or path of the feature from an established origin point on the feature. (DOI3)
Miles In Trail	A specified distance between aircraft, normally, in the same stratum associated with the same destination or route of flight. (FAA4)
Miles of Road Operated	The single or first main track, measured by the distance between terminals, over which railway transportation service is conducted. (AAR1)
Miles of Track	The number of tracks per one mile segment of right-of-way. Miles of track are measured without regard to whether or not rail traffic can flow in only one direction on the track. All track is counted, including yard track. (FTA1)
Miles of Track Operated	(See also Track Mile) Total track mileage consisting of first, second and other main tracks, and of yard tracks and sidings over which railway transportation service is conducted. (AAR1)
Miles Per Gallon (MPG)	A measure of vehicle fuel efficiency. Miles Per Gallon (MPG) represents "Fleet Miles per Gallon". For each subgroup or "table cell", MPG is computed as the ratio of the total number of miles traveled by all vehicles in the subgroup to the total number of gallons consumed. MPGs are assigned to each vehicle using the Environmental Protection Agency (EPA) certification files and adjusted for on-road driving. (DOE4) (DOE5)
Miles Per Gallon (MPG) Shortfall	The difference between actual on-road Miles Per Gallon (MPG) and Environmental Protection Agency (EPA) laboratory test MPG. Miles Per Gallon (MPG) shortfall is expressed as gallons per mile ratio (GPMR). (DOE4)
Milestone	The meaning given in CAA sections 182(g)(1) and 189(c) for serious and above ozone nonattainment areas and PM10 nonattainment areas, respectively. For all other nonattainment areas, a milestone consists of an emissions level and the date on which that level is to be achieved as required by the applicable CAA provision for reasonable further progress towards attainment.
Military Approach Controls	Military approach control facilities include Army Radar Approach Controls (ARACs), Radar Air Traffic Control Facilities (RATCFs), and Radar Approach Controls (RAPCONs). (FAA10)
Military Authority Assumes Responsibility For Aircraft Separation	A condition whereby the military services involved assume responsibility for separation between participating military aircraft in the Air Traffic Control (ATC) system. It is used only for required Instrument Flight Rules (IFR) operations which are specified in letters of agreement or other appropriate Force Module (FM) or military documents. (FAA4)
Military Base	An area owned and operated by the government in which various military activities take place. (DOI4)
Military Fuel	Kerosene-type jet fuel intended for military use. (DOE5)
Military Instrument Flight Rules (IFR) Training Route	Routes used by the Department of Defense and associated Reserve and Air Guard units for the purpose of conducting low altitude navigation and tactical training in both Instrument Flight Rules (IFR) and Visual Flight Rules (VFR) weather conditions below 10,000 feet Main Sea Level (MSL) at airspeeds in excess of 250 knots Indicated Airspeed (IAS). (FAA4)
Military Operations	All classes of military operations. (FAA13)
Military Operations Area (MOA)	An airspace assignment of defined vertical and lateral dimensions established outside positive control areas to separate/segregate certain military activities from Intermediate Fix (IF) traffic and to identify for Visual Flight Rules (VFR) traffic where these activities are conducted. (FAA8)
Military Training Route	Airspace of defined vertical and lateral dimensions established for the conduct of military flight training at airspeeds in excess of 250 knots IAS. (FAA4)
Milk Run	Easy trip. (ATA1)
Mill Capital	Cost for transportation and equipping a plant for processing ore or other feed materials. (DOE5)
Mini Landbridge	An intermodal system for transporting containers by ocean and then by rail or motor to a port previously served as an all-water move. (MARAD2)
Mini Service	Service station attendants pump vehicle fuel but do not provide other services, such as checking oil and tire pressure or washing windshields. (DOE5)
Miniature Railway	Small scale railway used for amusement. (DOI3)
Minibridge	(See also Intermodal, Landbridge) A joint water, rail or truck container move on a single Bill of Lading for a through route from a foreign port to a U.S. port destination through an intermediate U.S. port or the reverse. (MARAD1)
Minimum Altitude	Instrument Flight Rules (IFR) Minimum altitudes for Instrument Flight Rules (IFR) operations as prescribed in Federal Aviation Regulation (FAR) Part 91. These altitudes are published on aeronautical charts and prescribed in FAR Part 96 for airways and routes, and in FAR Part 97 for standard instrument approach procedures. If no applicable minimum altitude is prescribed in FAR Part 96 or FAR Part 97, the following minimum IFR altitude applies 1) In designated mountainous areas, 2,000 feet above the highest obstacle within a horizontal distance of 4 nautical miles from the course to be flown; 2) Other than mountainous areas, 1,000 feet above the highest obstacle within a horizontal distance of 4 nautical miles from the course to be flown; or 3) As otherwise authorized by the [Federal Aviation Administration (FAA)] Administrator or assigned by Air Traffic Control (ATC). (FAA4)
Minimum Crossing Altitude	The lowest altitude at certain fixes at which an aircraft must cross when proceeding in the direction of a higher minimum en route Instrument Flight Rules (IFR) altitude (MEA). (FAA4)
Minimum Descent Altitude	The lowest altitude, expressed in feet above mean sea level, to which descent is authorized on final approach or during circle-to-land maneuvering in execution of a standard instrument approach procedure, where no electronic glide slope is provided. (14CFR1)
Minimum Descent Altitude (MDA)	(See also Height Above Airport) The lowest altitude, expressed in feet above mean sea level, to which descent is authorized on final approach or during circle-to-land maneuvering in execution of a standard instrument approach procedure where no electronic glide slope is provided. (FAA4) (FAA8)
Minimum En Route Instrument Flight Rules (IFR) Altitude (MEA)	The lowest published altitude between radio fixes which assures acceptable navigational signal coverage and meets obstacle clearance requirements between those fixes. The Minimum En Route Altitude (MEA) prescribed for a federal airway, or segment thereof, area navigation low or high route, or other direct route applies to the entire width of the airway, segment, or route between the radio fixes defining the airway, segment or route. (FAA4) (FAA8)
Minimum Fuel	(See also Fuel Remaining) Indicates that an aircraft's fuel supply has reached a state where, upon reaching the destination, it can accept little or no delay. This is not an emergency situation but merely indicates an emergency situation is possible should any undue delay occur. (FAA4)
Minimum Holding Altitude	The lowest altitude prescribed for a holding pattern which assures navigational signal coverage, communications, and meets obstacle clearance requirements. (FAA4)
Minimum Instrument Flight Rule (IFR) Altitude (MIA)	Minimum altitudes for Instrument Flight Rules (IFR) operations as prescribed in Federal Aviation Regulations (FAR) Part 91. (FAA8)
Minimum Navigation Performance Specifications	A set of standards which require aircraft to have a minimum navigation performance capability in order to operate in minimum navigation performance specifications (MNPS) designated airspace. In addition, aircraft must be certified by their State of Registry for MNPS operation. (FAA4)
Minimum Navigation Performance Specifications Airspace (MNPSA)	Designated airspace in which minimum navigation performance specifications (MNPS) procedures are applied between MNPS certified and equipped aircraft. Under certain conditions, non-MNPS aircraft can operate in Minimum Performance Specifications Airspace (MNPSA). However, standard oceanic separation minima is provided between the non-MNPS aircraft and other traffic. Currently, the only designated MNPSA is described as follows 1) Between Flight Level 275 and 400; 2) Between latitudes 27-N. and the North Pole; 3) In the east, the eastern boundaries of the Control Areas (CTA) Santa Maria Oceanic, Shanwick Oceanic, and Reykjavik; 4) In the west, the western boundaries of CTA's Reykjavik and Gander Oceanic and New York Oceanic excluding the area west of 60-W and south of 38-30'N. (FAA4)
Minimum Obstruction Clearance Altitude	The lowest published altitude in effect between radio fixes on very high frequency (VHF) omnidirectional range (VOR) airways, off-airway routes or route segments which meets obstacle clearance requirements for the entire route segment and which assures acceptable navigational signal coverage only within 25 statute (22 nautical) miles of a VOR. (FAA4)
Minimum Pool Elevation	The least depth to which a pool is permitted to go and still maintain project channel depth. (TNDOT1)
Minimum Safe Altitude (MSA)	1) The minimum altitude specified in Federal Aviation Regulation (FAR) Part 91 for various aircraft operations; 2) Altitudes depicted on approach charts which provide at least 1,000 feet of obstacle clearance for emergency use within a specified distance from the navigation facility upon which a procedure is predicated. These altitudes will be identified as Minimum Sector Altitudes or Emergency Safe Altitudes and are established as follows a) Minimum Sector Altitudes. Altitudes depicted on approach charts which provide at least 1,000 feet of obstacle clearance within a 25-mile radius of the navigation facility upon which the procedure is predicated. Sectors depicted on approach charts must be at least 90 degrees in scope. These altitudes are for emergency use only and do not necessarily assure acceptable navigational signal coverage; b) Emergency Safe Altitudes. Altitudes depicted on approach charts which provide at least 1,000 feet of obstacle clearance in nonmountainous areas and 2,000 feet of obstacle clearance in designated mountainous areas within a 100-mile radius of the navigation facility upon which the procedure is predicated and normally used only in military procedures. These altitudes are identified on published procedures as "Emergency Safe Altitudes." (FAA4)
Minimum Safe Altitude Warning (MSAW)	A function of the Automated Radar Terminal System (ARTS) III computer that aids the controller by alerting him when a tracked Mode C equipped aircraft is below or is predicted by the computer to go below a predetermined minimum safe altitude. (FAA4) (FAA8)
Minimum Sector Altitude	The lowest altitude which may be used under emergency conditions which will provide a minimum clearance of 300 m (1,000 feet) above all obstacles located in an area contained within a sector of a circle of 46 km (25 nautical miles) radius centered on a radio aid to navigation. (FAA4)
Minimum Vectoring Altitude (MVA)	The lowest Mean Sea Level (MSL) altitude at which an Instrument Flight Rule (IFR) aircraft will be vectored by a Radar Controller, except as otherwise authorized for radar approaches, departures, and missed approaches. (FAA8)
Minimums	Weather condition requirements established for a particular operation or type of operation; e.g., Instrument Flight Rules (IFR) takeoff or landing, alternate airport for Instrument Flight Rules (IFR) flight plans, Visual Flight Rules (VFR) flights, etc. (FAA4)
Mining Danger Area	An area identified as a danger to maritime navigation due to unexploded ordinances. (DOI3)
Minivan	(See also Automobile, Bus, Car, Motor Vehicle) New type of small van that first appeared with that designation in 1984. Any of the smaller vans built on an automobile-type frame. Earlier models such as the Volkswagen van are now included in this category. (DOE4)
Minnie	Less than 100 pound shipment. (ATA1)
Minor Alteration	An alteration other than a major alteration. (14CFR1)
Minor Arterial	(See also Arterial Highway, Principal Arterial) Streets and highways linking cities and larger towns in rural areas in distributing trips to small geographic areas in urban areas (not penetrating identifiable neighborhoods). (NHTSA3)
Minor Arterials (Highway)	Roads linking cities and larger towns in rural areas. In urban areas, roads that link but do not penetrate neighborhoods within a community.
Minor Repair	A repair other than a major repair. (14CFR1)
Minutes In Trail	A specified interval between aircraft expressed in time. This method would more likely be utilized regardless of altitude. (FAA4)
Miscellaneous Transport Revenue	Other revenues associated with air transportation performed by air carriers, such as transportation fees collected from those traveling on free or reduced transportation and processing service charges such as lost tickets. (BTS4)
Missed Approach	(See also Go Around) 1) A maneuver conducted by a pilot when an instrument approach cannot be completed to a landing.The route of flight and altitude are shown on instrument approach procedure charts. A pilot executing a missed approach prior to the Missed Approach Point (MAP) must continue along the final approach to the MAP. The pilot may climb immediately to the altitude specified in the missed approach procedure; 2) A term used by the pilot to inform Air Traffic Control (ATC) that he is executing the missed approach; 3) At locations where ATC radar service is provided, the pilot should conform to radar vectors when provided by ATC in lieu of the published missed approach procedure. (FAA4)
Missed Approach Point	A point prescribed in each instrument approach procedure at which a missed approach procedure shall be executed if the required visual reference does not exist. (FAA4)
Missed Approach Procedure	The procedure to be followed if the approach cannot be continued. (FAA4)
Missed Executed Approach	Instructions issued to a pilot making an instrument approach which means continue inbound to the missed approach point and execute the missed approach procedure as described on the Instrument Approach Procedure Chart or as previously assigned by Air Traffic Control (ATC). The pilot may climb immediately to the altitude specified in the missed approach procedure upon making a missed approach. No turns should be initiated prior to reaching the missed approach point. When conducting an Airport Surveillance Radar (ASR) or Precision Approach Radar (PAR) approach, execute the assigned missed approach procedure immediately upon receiving instructions to "execute missed approach." (FAA4)
Missile	Sometimes applied to space launch vehicles, but more properly connotes automated weapons of warfare, i.e., a weapon which has an integral system of guidance, as opposed to the unguided rocket. (AIA1)
Miter Gates	Vertical, gates which form the openings of navigation locks; these gates consist of two swinging leaves and close at the center. (TNDOT1)
Miter Sill	The underwater concrete sill across the openings in the upper and lower lock chamber that the movable lock gates close on. The depth over these cells exceeds project depth and is registered on the several gages within the lock chamber. (TNDOT1)
Mixed Cargo	Indicates that a vessel carries any combination of grains, government aid, containers, general or bulk cargoes. (SLSDC1)
Mixed Trains	Mixed trains are passenger-carrying trains consisting of both passenger and freight cars. Freight cars, such as baggage cars, that are equipped with passenger-type braking and suspension systems, are considered to be passenger cars when utilized in passenger service. (FRA2)
Mobile Home	A housing unit built on a movable chassis and moved to the site. It may be placed on a permanent or temporary foundation and may contain one room or more. If rooms are added to the structure, it is considered a single-family housing unit. A manufactured house assembled on site is a single-family housing unit, not a mobile home. (DOE5)
Mobile Home Park	An area maintained for the parking of inhabited mobile homes. (DOI4)
Mobile Source	1) The mobile source-related pollutants are carbon monoxide (CO), hydrocarbons (HC), nitrogen oxides (NOx), and particulate matter (PM-10 and PM 2.5). 2) Mobile sources include motor vehicles, aircraft, seagoing vessels, and other transportation modes. The mobile source related pollutants are carbon monoxide (CO), hydrocarbons (HC) or volatile organic compounds (VOCs), nitrogen oxides (NOx), and small particulate matter (PM-10).
Mobile Source Air Toxics (MSATS)	Identified by the EPA, MSATs are the 21 hazardous air pollutants generated in large part by transportation sources.
Mobility	The ability to move or be moved from place to place.
Modal Share	The percentage of total freight moved by a particular type of transportation. (ATA2)
Modal Split	1) The proportion of total person trips that uses each of various specified modes of transportation. 2) The process of separating total person trips into the modes of travel used. 3) A term that describes how many people use alternative forms of transportation. It is frequently used to describe the percentage of people who use private automobiles, as opposed to the percentage who user public transportation. (TRB1)
Mode	A specific form of transportation, such as automobile, subway, bus, rail, or air.
Mode C Intruder Alert	(See also Conflict Alert) A function of certain air traffic control automated systems designed to alert radar controllers to existing or pending situations between a tracked target (known Instrument Flight Rules (IFR) or Visual Flight Rules (VFR) aircraft) and an untracked target (unknown Instrument Flight Rules (IFR) or Visual Flight Rules (VFR) aircraft) that require immediate attention/action. (FAA4)
Mode S	A secondary surveillance radar and communication system in which each aircraft is assigned a unique address code. Using this unique code, interrogations and other messages can be directed to a particular aircraft, and replies can be unambiguously identified. (FAA7)
Model Bow	A shaped, pointed bow. (TNDOT1)
Model Year	The year in which the particular style or design of vehicle was introduced or manufactured. (DOE4)
Monitor	When used with communication transfer, listen on a specific frequency and stand by for instructions. Under normal circumstances do not establish communications. (FAA4)
Monkey Line	Small hand line used by a lockman to throw down or bring up lockline. (TNDOT1)
Monorail	A single rail on which a vehicle or train of cars travels. (DOI3)
Monorail Vehicles	Guided transit passenger vehicles operating on or suspended from a single rail, beam or tube. (FTA1)
Mooring	A floating ball, can, or other structure, which is permanently secured to the harbor bottom by means of a heavy chain and anchor system and to which vessels are made fast, but able to swing to the wind and/or current. (BOC2)
Mooring Cell	(See also Dolphin) A river-front structure generally composed of steel piling or a cluster of wooden piles used for securing barges along the bank at loading facilities. (TNDOT1)
Moped	(See also Motorcycle, Motor-Driven Cycle) Includes motorized bicycles equipped with a small engine, typically 2 horsepower or less. Minibikes, dirt bikes, and trail bikes are excluded. Note that a motorized bicycle may or may not be licensed for highway use. (FHWA3)
Most Harmful Event	The event during a crash for a particular vehicle that is judged to have produced the greatest personal injury or property damage. (NHTSA3)
Most Restrictive State	The mode of an electric or electronic device that is equivalent to a track relay in its deenergized position. (49CFR236)
Motor Bus	A rubber-tired, self-propelled, manually-steered vehicle with fuel supply carried on board the vehicle. (APTA1)
Motor Buses, Class A (>35 seats)	Rubber tired passenger vehicles powered by diesel, gasoline, battery or alternative fuel engines contained witin the vehicle. Class A motor buses are equipped with more than 35 seats. (FTA1)
Motor Buses, Class B (25-35 seats)	Rubber tired passenger vehicles powered by diesel, gasoline, battery or alternative fuel engines contained witin the vehicle. Class B motor buses are equipped with 25 to 35 seats. (FTA1)
Motor Buses, Class C (<25 seats)	Rubber tired passenger vehicles powered by diesel, gasoline, battery or alternative fuel engines contained witin the vehicle. Class C motor buses are equippedwith less than 25 seats. (FTA1)
Motor Carrier	1) A for-hire motor carrier or a private motor carrier of property. The term "motor carrier" includes a motor carrier's agents, officers and representatives as well as employees responsible for hiring, supervising, training, assigning, or dispatching of drivers and employees concerned with the installation, inspection, and maintenance of motor vehicle equipment and/or accessories. 2) An employer firm that is primarily engaged in providing commercial motor freight or long distance trucking or transfer services. (49CFR390)
Motor Carrier of Passengers	A common, contract, or private carrier using a bus to provide commercial transportation of passengers. (23CFR658)
Motor Carrier Safety Administration (FMCS)	The Federal Motor Carrier Safety Administration (FMCSA) was established as a separate administration within the U.S. Department of Transportation on January 1, 2000, pursuant to the Motor Carrier Safety Improvement Act of 1999. The primary mission of FMCS is to reduce crashes, injuries, and fatalities involving large trucks and buses . FMCSA is headquartered in Washington, DC. We employ more than 1,000 individuals, in all 50 States and the District of Columbia, dedicated to improving bus and truck safety and saving lives.
Motor Freight Transportation Warehousing and Stockyards	Includes establishments that provide local or long-distance trucking or transfer services, warehousing and storage of farm products, furniture or other household goods, and commercial goods of a general nature. The operation of terminal facilities for handling freight, with or without maintenance facilities is also included. Stockyards, establishments that provide holding pens for livestock in transit, are included in this major group. These stock yards do not sell or auction livestock. (BEA1)
Motor Gasoline	A complex mixture of relatively volatile hydrocarbons, with or without small quantities of additives, obtained by blending appropriate refinery streams to form a fuel suitable for use in spark ignition engines. Motor gasoline includes both leaded and unleaded grades of finished motor gasoline, blending components, and gasohol. (DOE3) (DOE5)
Motor Home	Includes self-powered recreational vehicles (RV) that are operated as a unit without being towed by another vehicle (e.g., a Winnebago motor home). (FHWA3)
Motor Vehicle	A vehicle, machine, tractor, trailer, or semitrailer, or any combination thereof, propelled or drawn by mechanical power and used upon the highways in the transportation of passengers or property. It does not include a vehicle, locomotive, or car operated exclusively on a rail or rails, or a trolley bus operated by electric power derived from a fixed overhead wire, furnishing local passenger transportation similar to street-railway service. (49CFR171) (49CFR383) (49CFR390)
Motor Vehicle Accident	An unstabilized situation that includes at least one harmful event (injury or property damage) involving a motor vehicle in transport (in motion, in readiness for motion or on a roadway, but not parked in a designated parking area) that does not result from discharge of a firearm or explosive device and does not directly result from a cataclysm. (NSC1)
Motor Vehicle Chassis	The basic operative motor vehicle, including engine, frame, and other essential structures and mechanical parts, but excluding body and all accessories and auxiliary equipment. (GSA2)
Motor Vehicle Emissions Budget	The portion of the total allowable emissions defined in the submitted or approved control strategy implementation plan revision or maintenance plan for a certain date for the purpose of meeting reasonable further progress milestones or demonstrating attainment or maintenance of the NAAQS, for any criteria pollutant or its precursors, allocated to highway and transit vehicle use and emissions.
Motor Vehicle In Transport	A motor vehicle in motion on the trafficway or any other motor vehicle on the roadway, including stalled, disabled, or abandoned vehicles. (NHTSA3)
Motor Vehicle Traffic Accident	An accident involving a motor vehicle in use within the right-of-way or other boundaries of a trafficway open for the use of the public. (FHWA1) (NSC1)
Motor Vessel	Any vessel equipped with propulsion machinery (other than steam) more than sixty-five feet long. (USCG2)
Motorboat	Any vessel equipped with propulsion machinery, not more than sixty-five feet in length. (USCG2)
Motorbus	Rubber tired passenger vehicles which operate on roadways. Motorbus service implies fixed routes and schedules. (FTA1)
Motorbus (Transit)	A rubber-tired, self-propelled, manually steered bus with a fuel supply onboard the vehicle. Motorbus types include intercity, school, and transit.
Motorcycle	A two- or three-wheeled motor vehicle designed to transport one or two people, including motor scooters, minibikes, and mopeds.
Motor-Driven Cycle	(See also Moped, Motorcycle) A motorcycle with a motor that produces 5 brake horsepower or less. (49CFR571)
Motorized Vehicle	Includes all vehicles that are licensed for highway driving. Specifically excluded are snow mobiles and minibikes. (FHWA3)
Mouth	The exit or point of discharge of a stream into another stream, lake, or sea. (DOI4)
Movable Bridge	That section of a structure bridging a navigable waterway so designed that it may be displaced to permit passage of traffic on the waterway. (49CFR236)
Movable Bridge Locking	The rail locks, bridge locks, bolt locks, circuit controllers, and electric locks used in providing interlocking protection at a movable bridge. (49CFR236)
Movable Dam	A dam that is predominantly constructed of a series of wickets which may be raised or lowered as water stages dictate for passing water through the dam. These wickets may all be lowered at the bed of the river and vessels may pass over the dam during periods of high water. The dam and/or river is then said to be "open". (TNDOT1)
Movement Area	1) The runways, taxiways, and other areas of an airport/heliport which are utilized for taxiing/hover taxiing, air taxiing, takeoff, and landing of aircraft, exclusive of loading ramps and parking areas. At those airports/heliports with a tower, specific approval for entry onto the movement area must be obtained from ATC. 2) That part of an aerodrome to be used for the takeoff, landing and taxiing of aircraft, consisting of the maneuvering area and the apron(s). (FAA4)
Moving Target Indicator	An electronic device which will permit radar scope presentation only from targets which are in motion. A partial remedy for ground clutter. (FAA4)
Mu Locomotive	A multiple operated electric locomotive described in 49 CFR 229.4 paragraph (i)(2) or (3). (49CFR229)
Mule	Small tractor used in warehouse to pull two axle dollies, also yard tractor. (ATA1)
Mule Train	The maneuver of towboats in ice-choked channels whereby the tow is strung out single file, the barges fitted with loose couplings or lashings, and the tow pulled behind the towboat. Also known as string out. (TNDOT1)
Multi Stop Body	Fully enclosed truck body with driver's compartment designed for quick, easy entrance and exit. (ATA1)
Multicom	A mobile service not open to public correspondence used to provide communications essential to conduct the activities being performed by or directed from private aircraft. (FAA4)
Multimodal	The availability of transportation options using different modes within a system or corridor.
Multimodal Transportation	Often used as a synonym for intermodalism. Congress and others frequently use the term intermodalism in its broadest interpretation as a synonym for multimodal transportation. Most precisely, multimodal transportation covers all modes without necessarily including a holistic or integrated approach. (BTS2)
Multiple Runway	The utilization of a dedicated arrival runway(s) for departures and a dedicated departure runway(s) for arrivals when feasible to reduce delays and enhance capacity. (FAA4)
Multipurpose Passenger Vehicle	A motor vehicle with motive power, except a trailer, designed to carry 10 persons or less which is constructed either on a truck chassis or with special features for occasional off-road operation. (49CFR571)
Multi-Trailer Five or Less Axle Truck	All vehicles with five or less axles consisting of three or more units, one of which is a tractor or straight truck power unit. (FHWA2)
Multi-Trailer Seven or More Axle Truck	All vehicles with seven or more axles consisting of three or more units, one of which is a tractor or straight truck power. (FHWA2)
Multi-Trailer Six Axle Truck	All six axle vehicles consisting of three or more units, one of which is a tractor or straight truck power-unit. (FHWA2)
Naphtha	A generic term applied to a petroleum fraction with an approximate boiling range between 122 and 400 degrees Fahrenheit. (DOE3)
Naphtha-Type Jet Fuel	A fuel in the heavy naphtha boiling range with an average gravity of 52.8 degrees American Petroleum Institute (API) and 20 to 90 percent distillation temperatures of 290 degrees to 470 degrees Fahrenheit, meeting Military Specification MIL-T-5624L (Grade JP-4). JP-4 is used for turbojet and turboprop aircraft engines, primarily by the military. Excludes ram-jet and petroleum rocket fuels. (DOE5) (DOE6)
Narrow Channel	Channel with very little room to spare. (TNDOT1)
Narrow Railway Gauge	Distance between the rails of a track less than 4 ft 8.5 inches. (DOI3)
National Airspace System (NAS)	The common network of U.S. airspace; air navigation facilities, equipment, and services; airports or landing areas; aeronautical charts, information, and services; rules, regulations, and procedures; technical information, manpower, and material. Included are system components shared jointly with the military. (FAA4) (FAA8)
National Airspace System (NAS) Stage A	The en route Air Traffic Control (ATC) system's radar, computers and computer programs, controller plan view displays (Plan View Displays (PVD)/Radar Scopes), input/output devices, and the related communications equipment which are integrated to form the heart of the automated Instrument Flight Rules (IFR) air traffic control system This equipment performs Flight Data Processing (FDP) and Radar Data Processing (RDP). It interfaces with automated terminal system and is used in the control of en route Instrument Flight Rules (IFR) aircraft. (FAA4)
National Ambient Air Quality Standards (NAAQS)	Federal standards that set allowable concentrations and exposure limits for various pollutants. The EPA developed the standards in response to a requirement of the CAA. Air quality standards have been established for the following six criteria pollutants: ozone (or smog), carbon monoxide, particulate matter, nitrogen dioxide, lead, and sulfur dioxide.
National Beacon Code Allocation Plan Airspace	Airspace over United States territory located within the North American continent between Canada and Mexico, including adjacent territorial waters outward to about boundaries of oceanic control areas (CTA)/Flight Information Regions (FIR). (FAA4)
National Boating Safety Advisory Council (NBSAC)	A 21 member council, equally represented by industry, the public, and State Boating Law Administrators, with expertise, knowledge and experience in boating safety. The Council acts in an advisory or consulting capacity to the Commandant. (USCG1)
National Bridge Inspection Standards (NBIS)	Federal regulations establishing requirements for inspection procedures, frequency of inspections, qualifications of personnel, inspection reports, and preparation and maintenance of a State bridge inventory. (FHWA6)
National Bridge Inventory (NBI)	The aggregation of structure inventory and appraisal data collected to fulfill the requirements of the National Bridge Inspection Standards that each State shall prepare and maintain an inventory of all bridges subject to the National Bridge Inspection Standards. (FHWA6)
National Carrier Group	Air carrier groups with annual operating revenues between $100,000,000 and $1,000,000,000. (BTS4) (BTS5) (BTS6) (FAA11)
National Cooperative Highway Research Program (NCHRP)	The cooperative research, development, and technology transfer (RD&T) program directed toward solving problems of national or regional significance identified by States and the FHWA, and administered by the Transportation Research Board, National Academy of Sciences. (23CFR420)
National Cooperative Transit Research and Development Program	A program established under Section 6a) of the Urban Mass Transportation Act of 1964, as amended, to provide a mechanism by which the principal client groups of the Urban Mass Transportation Administration can join cooperatively in an attempt to resolve near-term public transportation problems through applied research, development, testing, and evaluation. NCTRP is administered by the Transportation Research Board. (TRB1)
National Environmental Policy Act of 1969 (NEPA)	Established a national environmental policy requiring that any project using federal funding or requiring federal approval, including transportation projects, examine the effects of proposed and alternative choices on the environment before a federal decision is made.
National Flight Data Center	A facility in Washington DC, established by Federal Aviation Administration (FAA) to operate a central aeronautical information service for the collection, validation, and dissemination of aeronautical data in support of the activities of government, industry, and the aviation community. The information is published in the National Flight Data Digest. (FAA4)
National Flight Data Digest	A daily (except weekends and Federal holidays) publication of flight information appropriate to aeronautical charts, aeronautical publications, Notices to Airmen, or other media serving the purpose of providing operational flight data essential to safe and efficient aircraft operations. (FAA4)
National Highway System (NHS)	This system of highways designated and approved in accordance with the provisions of 23 U.S.C. 103b). (23CFR500)
National Highway Traffic Safety Administration (NHTSA)	The Administration was established by the Highway Safety Act of 1970 (23 U.S.C. 401 note). The Administration was established to carry out a congressional mandate to reduce the mounting number of deaths, injuries, and economic losses resulting from motor vehicle crashes on the Nation's highways and to provide motor vehicle damage susceptibility and ease of repair information, motor vehicle inspection demonstrations and protection of purchasers of motor vehicles having altered odometers, and to provide average standards for greater vehicle mileage per gallon of fuel for vehicles under 10,000 pounds (gross vehicle weight). (OFR1)
National Historic Trail (NHT)	A historic or prehistoric route of travel of significance to the entire Nation. It must meet three criteria listed in Section 5(b)(11) of the National Trails System Act, and be established by Act of Congress. 16 U.S.C. 1241-51.
National Income	The aggregate earnings of labor and property which arise in the current production of goods and services by the nation's economy. (DOE6)
National Inland Waterways Transport	Inland waterways transport between two places (a place of IWT loading/embarkment and a place of unloading/disembarking) located in the same country irrespective of the country in which the IWT vessel is registered. It may involve transit through a second country. (TNDOT1)
National Inland Waterways Transport Vessel	Inland Waterways Transport (IWT) vessel which is registered at a given date in the reporting country. (TNDOT1)
National ITS Architecture	A systems framework to guide the planning and deployment of ITS infrastructure. The national ITS architecture is a blueprint for the coordinated development of ITS technologies in the U.S. It is unlikely that any single metropolitan area or state would plan to implement the entire national ITS architecture.
National Scenic Byways Program (NSBP)	Designates roads that have outstanding scenic, historic, cultural, natural, recreational, and archaeological qualities as All-American Roads or National Scenic Byways, and provides grants for scenic byway projects. 23 U.S.C. 162
National Scenic Trail (NST)	A continuous, primarily nonmotorized route of outstanding recreation opportunity, established by Act of Congress. 16 U.S.C. 1241-51.
National Search and Rescue Plan	An interagency agreement which provides for the effective utilization of all available facilities in all types of search and rescue missions. (FAA4)
National Trails System (NTS)	The network of scenic, historic, and recreation trails created by the National Trails System Act of 1968. These trails provide for outdoor recreation needs, promote the enjoyment, appreciation, and preservation of open-air, outdoor areas and historic resources, and encourage public access and citizen involvement. 16 U.S.C. 1241-51.
National Transit Database	(Formerly Section 15) A reporting system, by uniform categories, to accumulate mass transportation financial and operating information and a uniform system of accounts and records. The reporting and uniform systems shall contain appropriate information to help any level of government make a public sector investment decision. The Secretary [of Transportation] may request and receive appropriate information from any source. (FTA1)
National Transportation System	An intermodal system consisting of all forms of transportation in a unified, interconnected manner to reduce energy consumption and air pollution while promoting economic development and supporting the Nation's preeminent position in international commerce. The NTS includes the National Highway System (NHS), public transportation and access to ports and airports. (APTA1)
Nationals (Air)	Air carrier groups with annual operating revenues between $100 million and $1 billion.
Nation's Freight Bill	The amount spent annually on freight transportation by the nation's shippers; also represents the total revenue of all carriers operating in the nation. (ATA2)
Nationwide Personal Transportation Survey (NPTS)	A nationwide home interview survey of households that provides information on the characteristics and personal travel patterns of the U.S. population. Surveys were conducted in 1969, 1977, 1983 and 1990 by the U.S. Bureau of Census for the U.S. Department of Transportation. (DOE6)
Native American Local Technical Assistance Programs	Primarily responsible for transportation related technology transfer to Native Americans through Tribal Technical Assistance Program (TTAP) Centers.
Natural Gas	A naturally occurring mixture of hydrocarbon and nonhydrocarbon gases found in porous geologic formations beneath the Earth’s surface, often in association with petroleum. The principal constituent is methane.
Natural Gas Marketed Production	Gross withdrawals of natural gas from production reservoirs, less gas used for reservoir repressuring; nonhydrocarbon gases removed in treating and processing operations; and quantities vented and flared. (DOE3)
Natural Gas Plant Liquids	Liquids recovered from natural gas in processing plants or field facilities, or extracted by fractionators. They include ethane, propane, normal butane, isobutane, pentanes plus, and other products, such as finished motor gasoline, finished aviation gasoline, special naphthas, kerosene, and distillate fuel oil produced at natural gas processing plants.
Natural Gas Policy Act of 1978 (NGPA)	Section 311 Construction, allows an interstate pipeline company to transport gas "on behalf of" any intrastate pipeline or local distribution company. Pipeline companies may expand or construct facilities used solely to enable this transportation service, subject to certain conditions and reporting requirements. (DOE1)
Natural Gas Transmission	Establishments engaged in the transmission and/or storage of natural gas for sale. (BOC1)
Natural Gas Transmission and Distribution	Establishments engaged in both the transmission and distribution of natural gas for sale. (BOC1)
Navigable Airspace	Airspace at and above the minimum flight altitudes prescribed in the Federal Aviation Regulations (FARs) including airspace needed for safe takeoff and landing. (FAA4)
Navigable Canal	Waterway built primarily for navigation. (TNDOT1)
Navigable Inland Waterway	A stretch of water, not part of the sea, over which vessels of a carrying capacity of not less than 50 tons can navigate when normally loaded. This term covers both navigable rivers and lakes and navigable canals. (TNDOT1)
Navigable Lake	Natural expanse of water open for navigation. (TNDOT1)
Navigable Pass	The water pass through which vessels may pass over a movable dam during periods of high water. The wickets of the dam are lowered to the riverbed and the water flows with little or no obstruction. Navigable passes are usually from 600 feet to 900 feet in width when the dam is lowered. These are found only in the Ohio and Illinois rivers. (TNDOT1)
Navigable River	Natural waterway open for navigation irrespective of whether it has been improved for that purpose. (TNDOT1)
Navigable Waters	The waters of the United States, including the territorial sea and such waters as lakes, rivers, streams; waters which are used for recreation; and waters from which fish or shellfish are taken and sold in interstate or foreign commerce. (49CFR171) (49CFR194)
Navigable Waters of the U.S.	Waters of the United States that are subject to the ebb and flow of the tide, and/or are presently used, or have been used in the past, or may be susceptible to use to transport interstate or foreign commerce. (TNDOT1)
Navigation Aid (NAVAID)	Includes electrical and visual air navigation aids, lights, signs, and their supporting equipment. (FAA12)
Navigation Aid (NAVAID) Classes	Very high frequency omni-directional radio range (VOR), combined Very High Frequency Omni-Directional Radio Range (VOR) and tactical aircraft control and navigation (TACAN) navigational facility (VORTAC), and TACAN aids are classed according to their operational use. The three classes of NAVAIDs are T-Terminal, L-Low altitude, H-High altitude. (FAA4)
Navigation Bulletin	See Public Notice.
Navigational Aid	(See also Air Navigation Facility) Any visual or electronic device airborne or on the surface which provides point-to-point guidance information or position data to aircraft in flight. (FAA4)
Near Midair Collision	An incident associated with the operation of an aircraft in which a possibility of collision occurs as a result of proximity of less than 500 feet to another aircraft, or a report is received from a pilot or flight crew member stating that a collision hazard existed between two or more aircraft. (FAA3) (FAA10)
Near Midair Collision (Air)	An incident in which the possibility of a collision occurred as a result of aircraft flying with less than 500 feet of separation, or a report received from a pilot or flight crew member stating that a collision hazard existed between two or more aircraft.
Needle	A long stick of timber placed between the wickets of a movable dam to stop the leakage of water between the gates. A needle flat is a small barge used in transporting these timbers. (TNDOT1)
Negative	"No", or "Permission not granted", or "That is not correct." (FAA4)
Negative Contact	Used by pilots to inform Air Traffic Control (ATC) that 1) Previously issued traffic is not in sight. It may be followed by the pilot's request for the controller to provide assistance in avoiding the traffic. 2) They were unable to contact ATC on a particular frequency. (FAA4)
Neo bulk Cargo	Shipments consisting entirely of units of a single commodity, such as cars, lumber, or scrap metal.
Net Horsepower	The usable power output of an engine "as installed". Net horsepower is the gross horsepower minus the horsepower used to drive the alternator, water pump, fan, etc., at a specified rpm. (GSA2)
Net Income or Loss Before Income Taxes	The Operating Profit or (Loss) which is operating revenues less operating expenses less nonoperating income and expense produces the Net Income, but before "nonrecurring items." (BTS4)
Net Maximum Dependable Capacity	The gross electrical output measured at the output terminals of the turbine generator(s) during the most restrictive seasonal conditions, less the station service load. (DOE5)
Net Module Shipments	Represents the difference between module shipments and module purchases. When exported, incomplete modules and unencapsulated cells are also included. (DOE5)
Net Receipts	The difference between total movements into and total movements out of each PAD District by pipeline, tanker, and barge. (DOE5)
Net Tare Weight	The weight of an empty cargo-carrying piece of equipment plus any fixtures permanently attached. (MARAD2)
Net Ton Mile	The movement of revenue and/or non revenue freight a distance of one mile. Includes a reasonable portion of the weight of exclusive work equipment and motorcar trains moved one mile. (AAR1)
Net Tonnage	The net or register tonnage of a vessel is the remainder after deducting from the gross tonnage of the vessel the tonnage of crew spaces, master's accommodations, navigation spaces, allowance for propelling power, etc. It is expressed in tons of 100 cubic feet. (USGC4)
Net Weight	(See also Gross Weight) Weight of the goods alone without any immediate wrappings, (e.g., the weight of the contents of a tin can without the weight of the can). (TNDOT1)
Network Navigable Inland Waterway	All navigable inland waterways open to public navigation in a given area. (TNDOT1)
New Look Bus	A bus with the predominant styling and mechanical equipment common to buses manufactured between 1959 and 1978. (APTA1)
New Vehicle	A vehicle which is offered for sale or lease after manufacture without any prior use. (49CFR37)
New Vehicle Storage	A Fleet Management System (FMS) inventory status indicating vehicles that are placed in storage when first received and are awaiting assignment. (GSA2)
Night	From 600 p.m. to 5:59 a.m. (NHTSA3)
Nine Foot Contour Line	A meandering line not necessarily on the channel edge at which a depth of 9 feet is obtained at river stage low water reference plain. (TNDOT1)
Nitrogen Oxide Emissions	Nitrogen oxides (NOx), the term used to describe the sum of nitric oxide (NO), nitrogen dioxide (N02) and other oxides of nitrogen, play a major role in the formation of ozone. The major sources of man?made NOx emissions are high?temperature combustion processes, such as those occurring in automobiles and power plants.
Nitrogen Oxides	A product of combustion of fossil fuels whose production increases with the temperature of the process. It can become an air pollutant if concentrations are excessive. (DOE6)
No Gyro Approach	A radar approach/vector provided in case of a malfunctioning gyro-compass or directional gyro. Instead of providing the pilot with headings to be flown, the controller observes the radar track and issues control instructions "turn right/left" or "stop turn" as appropriate. (FAA4)
Noise Standards	23 U.S.C. 109(i)
Non Revenue Freight	Company materials and supplies transported without charge in freight trains of a particular railroad for its own use. (AAR1)
Nonattainment Area (NAA)	Any geographic area that has not met the requirements for clean air as set out in the Clean Air Act of 1990.
Non-Bulk Packaging	A packaging which has 1) A maximum capacity of 450 L (119 gallons) or less as a receptacle for a liquid; 2) A maximum net mass of 400 kg (882 pounds) or less and a maximum capacity of 450 L (119 gallons) or less as a receptacle for a solid; or 3) A water capacity of 454 kg (1000 pounds) or less as a receptacle for a gas as defined in 49CFR173.115. (49CFR171)
Noncoincidental Peak-Day Flow	The largest volume of gas delivered to a particular customer by a pipeline company in a single day during the year. (DOE1)
Non-Collision Accident	A motor vehicle accident which does not involve a collision. Non-collision accidents include jackknifes, overturns, fires, cargo shifts and spills, and incidents in which trucks run off the road. (FHWA2)
Noncollision Crash	A class of crash in which the first harmful event does not involve a collision with a fixed object, non-fixed object, or a motor vehicle. This includes overturn, fire/explosion, falls from a vehicle, and injuries in a vehicle. (NHTSA3)
Noncompliance	Failure to comply with a standard or regulation issued under 46 U.S.C. Chapter 43, or with a section of the statutes. (USCG1)
Noncurrent Liabilities	Non-current portion of long-term debt and of capital leases, advances to associated companies and other liabilities not due during the normal business cycle. (BTS4)
Non-Earthen Shore	A structure built of stone, brick, concrete, or other building materials, that borders a body of water and that is not otherwise classified. (DOI3)
Nonfatal (Most Serious) Injured	Are nonfatally injured persons whose injury is classified as incapacitating (as defined in the "Manual On Classification of Motor Vehicle Traffic Accidents," American National Standards Institute (ANSI) D16.1-1989). States may receive information about these injuries on the accident report forms as incapacitating, incapacitating injury, incapacitated, disabled, carried from scene, severe injury, critical nonfatal, major injury, or other similar terms. (FHWA2)
Nonfatal Accident	A motor vehicle traffic accident that results in one or more injuries, but no fatal injuries. (FHWA1)
Nonfatal Alcohol Involvement Crash	Alcohol-related or alcohol-involved if police indicate on the police accident report that there is evidence of alcohol present. The code does not necessarily mean that a driver, passenger, or non-occupant was tested for alcohol. (NHTSA3)
Nonfatal Casualty	Injuries and occupational illnesses incurred during railroad operations and maintenance procedures. (FRA3)
Nonfatal Injury	A nonfatal injury is any traffic accident injury other than a fatal injury. (FHWA2) (FHWA5)
Nonfatal Injury Accident	A nonfatal injury accident is a traffic accident that results in nonfatal injuries. (FHWA5)
Nonfatal Injury Accident Rate	The nonfatal injury accident rate is the number of nonfatal injury accidents per 100 million vehicle miles of travel. (FHWA5)
Nonfatally Injured Person	A nonfatally injured person is one who suffers a nonfatal injury in either a fatal or nonfatal injury traffic accident. (FHWA5)
Nonfatally Injured Persons Rate	The nonfatally injured persons rate is the number of nonfatally injured persons per 100 million vehicle miles of travel. (FHWA5)
Non-Fixed Guideway Directional Route Miles	The mileage operated by non-rail modes on fixed routes and schedules in mixed traffic right-of-way. (FTA1)
Non-Fixed Route	Service not provided on a repetitive, fixed-schedule basis along a specific route to specific locations. Demand response is the only non-fixed-route-mode. (APTA1)
Nonhub	A community enplaning less than 0.05 percent of the total enplaned passengers in all services and all operations in all communities within the 50 States, and District of Columbia, and other U.S. areas designated by the Federal Aviation Administration. (FAA2) (FAA14) (FAA15)
Nonincapacitating Evident Injury	Any injury, other than a fatal injury or an incapacitating injury, evident to observers at the scene of the accident. Includes lumps on head, abrasions, bruises, minor lacerations, and others. Excludes limping.
Nonmetropolitan	Households not located within Metropolitan Statistical Areas (MSA) as defined by the U.S. Office of Management and Budget. (DOE4) (DOE5)
Non-Motorist	Any person who is not an occupant of a motor vehicle in transport and includes the following 1) Pedestrians, 2) Pedalcyclists, 3) Occupants of parked motor vehicles, 4) Others such as joggers, skateboard riders, people riding on animals, and persons riding in animal-drawn conveyances. (NHTSA3)
Non-Motorist Location	The location of non motorists at time of impact. Intersection locations are coded only if non motorists were struck in the area formed by a junction of two or more traffic ways. Non-intersection location may include non-motorists struck on a junction of a driveway/alley access and a named traffic way. Non-motorists who are occupants of motor vehicles not in transport are coded with respect to the location of the vehicle. (NHTSA3)
Non-Occupant	Any person who is not an occupant of a motor vehicle (e.g., pedestrian or pedalcyclist), or who is an occupant of a motor vehicle which is not in transport. (NHTSA1)
Nonoccupant (Automobile)	Any person who is not an occupant of a motor vehicle in transport (e.g., bystanders, pedestrians, pedalcyclists, or an occupant of a parked motor vehicle).
Nonoperating Income and Expense	Interest income and expense, unusual foreign exchange gains or losses, and capital gains or losses in disposition or property and equipment. (BTS4)
Non-Pilot Personnel	May include any of the following personnel Rules, Regulations, Standards, Maintenance, Servicing, Inspection, Weather Service, Airport Management, Production-Design, Ground Signalman, Passenger, Driver of Vehicle, Flight Engineer, Radio Operator, Flight Instructor on ground, Operational Supervisor, Air Traffic Control, Airway Facilities, Pilot of another aircraft, Ground Crewman, Spectator, Third Pilot, Navigator, Flight Attendant, Dispatching and other flight personnel. (NTSB1)
Non-Port Terminal	Waterfront terminals individually located along the navigable rivers, having place identity but not otherwise classifiable as a regional distribution or subregional port. (TNDOT1)
Nonprecision Approach Procedure	A standard instrument approach procedure in which no electronic glide slope is provided. (14CFR1)
Non-Precision Instrument Runway	A runway with an approved or planned straight-in instrument approach procedure which has no existing or planned precision instrument approach procedure. (FAA12)
Nonpriority U.S. Mail	Mail bearing postage for surface transportation that goes by air on a space available basis at rates lower than those fixed for priority (i.e., air) mail. (BTS5)
Non-Radar Approach Control Tower	An airport traffic control tower (ATCT) providing approach control service without the use of radar. In other words, an ATCT at which air traffic control specialists are permitted to provide manual approach control service, as well as to handle takeoffs and landings. (FAA10) (FAA13)
Nonrecurring Items	Discontinued operations, extraordinary items and accounting changes income or loss. (BTS4)
Non-Regulated Trucking	A carrier which is exempt from economic regulation, e.g. exempt agricultural shipments and private trucking operations. (ATA2)
Nonresident Commercial Driver's License	A commercial driver's license (CDL) issued by a State to an individual domiciled in a foreign country. (49CFR383)
Nonscheduled Air Transportation	Establishments primarily engaged in furnishing nonscheduled air transportation. Also included in this industry are establishments primarily engaged in furnishing airplane sightseeing services, air taxi services and helicopter passenger transportation services to, from, or between local airports, whether or not scheduled. (BOC1)
Nonscheduled Service	Revenue flights, such as charter flights, that are not operated in regular scheduled service, and all nonrevenue flights incident to such flights. (BTS4) (BTS5) (BTS6) (NTSB1)
Nonscheduled Service (Air)	Revenue flights not operated as regular scheduled service, such as charter flights, and all nonrevenue flights incident to such flights.
Non-Self Propelled	Vessels not containing within themselves the means for their own propulsion. (TNDOT1)
Nonself-Propelled Vessel (Water)	A vessel without the means for self-propulsion. Includes dry cargo barges and tanker barges.
Nontrain Incident	An event that results in a reportable casualty, but does not involve the movement of ontrack equipment and does not cause reportable damage above the threshold established for train accidents.
Non-Train Incident	An event arising from railroad operations but not from the movement of on-track equipment, which does not exceed the reporting threshold, and results in a death, a reportable injury, or a reportable occupational illness. (FRA3) (FRA4)
Nontrespassers	A person who is lawfully on any part of railroad property which is used in railroad operations or a person who is adjacent to railroad premises when injured as a result of railroad operations. (FRA3)
Nontrespassers (Class D)	Persons lawfully on that part of railroad property that is used in railroad operation (other than those herein defined as employees, passengers, trespassers, or contractor employees) and persons adjacent to railroad premises when they are injured as the result of the operation of a railroad. This class also includes other persons on vessels or buses, whose use arises from the operation of a railroad. (FRA2)
Nontrespassers (Rail)	A person lawfully on any part of railroad property used in railroad operations or a person adjacent to railroad premises when injured as the result of railroad operations.
Non-Vehicle Maintenance	All activities associated with facility maintenance, including administration; repair of buildings, grounds and equipment as a result of accidents or vandalism; operation of electric power facilities; and, maintenance of vehicle movement control systems; fare collection and counting equipment; structures, tunnels and subways; roadway and track; passenger stations, operating station buildings, grounds and equipment; communication systems; general administration buildings, grounds and equipment; and electric power facilities. (FTA1)
Nonvessel Operating Common Carrier (NVOCC)	1) A company operating as a freight forwarder involved in ocean-going vessel freight only. 2) A form of freight consolidation for the selling of space on ocean-going vessels. (BOC2)
Nonvessel Owning Carrier (NVOC)	A firm which consolidates and disperses international containers that originate at, or are bound for, inland ports. (USTTA1)
Nonvessel-Casualty-Related Death (Water)	A death that occurs onboard a commercial vessel but not as a result of a vessel casualty, such as a collision, fire, or explosion.
Nordo	See Lost Communications.
Normal Pool	The stage of an artificially impounded water body that prevails for the greater part of the year. (DOI3)
Normal Pool Elevation	Height in feet above sea level at which a section of the river is to be maintained behind the dam. (TNDOT1)
Normal Pool Stage	That level of the river maintained by the desired dam operations. (TNDOT1)
Nose Dive	Trailer tipped forward on its nose. (ATA1)
Nose'er In	To land by putting the bow of the boat into the bank. (TNDOT1)
Not Paved Surface	All surfaces other than asphalt or concrete. (DOI3)
Notch	A void or opening or any place where barge head logs do not meet, where they are not even with each other, or where no other barge is faced to a barge. (TNDOT1)
Notes and Accounts Receivable	Current notes and accounts receivable which are reasonably expected to be amortized within one year. These receivables include passenger receivables for air travel to be performed both by the selling carrier and other airlines, for which the related liabilities (to passenger or to the performing air carrier) are included in the "air traffic liabilities" account. (BTS4)
Notice of Funding Availability	Written notice to the respective area tribes that the BIA area office has received contractible program funds.
Notice of Proposed Rulemaking (NPRM)	A public notice of proposed regulations required by law, which allows for public comments and scheduling of public hearings. (USCG1)
Notice to Airmen (NOTAM)	A notice containing information (not known sufficiently in advance to publicize by other means) concerning the establishment, condition, or change in any component (facility, service, or procedure of, or hazard to the national airspace system), the timely knowledge of which is essential to personnel concerned with flight operations. (FAA2) (FAA7) (FAA8)
Notice to Mariners	(See also Public Notice) A bulletin or information to mariners issued by the Coast Guard. (TNDOT1)
Notices to Airmen Publication (NTAP)	A publication issued every 14 days, designed primarily for the pilot, which contains current Notice to Airmen (NOTAM) information considered essential to the safety of flight as well as supplemental data to other aeronautical publications. The contraction NTAP is used in NOTAM text. (FAA4)
Numbered Vessel	An undocumented vessel numbered by a state with an approved numbering system or by the Coast Guard under Chapter 123 of title 46, U.S.C. (USCG2)
Numerous Targets Vicinity (Location)	A traffic advisory issued by Air Traffic Control (ATC) to advise pilots that targets on the radar scope are too numerous to issue individually. (FAA4)
Oakie Blower	Air scoop on air intake to increase power. (ATA1)
Object	Includes, but is not limited to above ground structures, people, equipment, vehicles, natural growth, terrain, and parked aircraft. (FAA12)
Object Class	As the term is used in expense classification, an object is an article or service obtained. An object class is a grouping of expenses on the basis of goods or services purchased. The object classes include salaries and wages, fringe benefits, services, materials and supplies, and other expenses as defined in Section 7.2, Volume II of the Uniform System of Accounts (USOA). (FTA1)
Object Free Area (OFA)	A two dimensional ground area surrounding runways, taxiways, and taxilanes which is clear of objects except for Navigation Aids (NAVAIDs) and objects whose location is fixed by function. (FAA12)
Objectives	Specific, measurable statements related to the attainment of goals.
Objects Not Fixed	Objects that are movable or moving but are not motor vehicles. Includes pedestrians, pedalcyclists, animals, or trains (e.g., spilled cargo in roadway). (NHTSA3)
Obligation	The Federal government’s legal commitment (promise) to pay or reimburse the States or other entities for the Federal share of a project’s eligible costs.
Obligation Ceiling	Identical to obligation limitation. A restriction, or "ceiling" on the amount of Federal assistance that may be promised (obligated) during a specified time period.
Obligation Limitation	A restriction, or "ceiling" on the amount of Federal assistance that may be promised (obligated) during a specified time period. This is a statuatory budgetary control that does not affect the apportionment or allocation of funds. Rather, it controls the rate at which these funds may be used.
Obligational Authority (OA )	The total amount of funds that may be obligated in a year. For the Federal-Aid Highway Program this is comprised of the obligation limitation amount plus amounts for programs exempt from the limitation.
Obligations Under Capital Leases (Current and Noncurrent)	Liability applicable to property obtained under capital leases. (BTS4)
Obstacle	An existing object, object of natural growth, or terrain at a fixed geographical location or which may be expected at a fixed location within a prescribed area with reference to which vertical clearance is or must be provided during flight operation. (FAA4) (FAA8)
Obstacle Free Zone (OFZ)	(See also Inner-Approach Obstacle Free Zone, Inner-Transitional Obstacle Free Zone, Runway Obstacle Free Zone) The obstacle free zone (OFZ) is a three dimensional volume of airspace which protects for the transition of aircraft to and from the runway. The Obstacle Free Zone (OFZ) clearing standard precludes taxiing and parked airplanes and object penetrations, except for frangible navigation aid (NAVAID) locations that are fixed by function. Additionally, vehicles, equipment, and personnel may be authorized by air traffic control to enter the area using the provisions of Order 7110.65, Air Traffic Control, paragraph 3-5. The runway OFZ and when applicable, the inner-approach OFZ, and the inner-transitional OFZ, comprise the OFZ. (FAA4)
Obstruction	Any object/obstacle exceeding the obstruction standards specified by Federal Aviation Regulations (FAR) Part 77, Subpart G. (FAA4) (FAA8)
Obstruction Accident	An accident/incident consisting of striking 1) A bumping post or a foreign object on the track right-of-way; 2) A highway vehicle at a location other than a highway-rail crossing site; derailed equipment; or 3) A track motorcar or similar work equipment not equipped with Association of American Railroad couplers, and not operating under train rules. (FRA2)
Obstruction Light	A light or one of a group of lights, usually red or white, frequently mounted on a surface structure or natural terrain to warn pilots of the presence of an obstruction. (FAA8)
Obstruction to Air Navigation	An object of greater height than any of the heights or surfaces presented in Subpart C of Federal Aviation Regulations (FAR) Part 77. (FAA12)
Occupancy	The number of persons, including driver and passenger(s) in a vehicle. Nationwide Personal Transportation Survey (NPTS) occupancy rates are generally calculated as person miles divided by vehicle miles. (FHWA3)
Occupant	Any person who is in or upon a motor vehicle in transport. Includes the driver, passengers, and persons riding on the exterior of a motor vehicle (e.g., a skateboard rider who is set in motion by holding onto a vehicle). (NHTSA3)
Occupant (Highway)	Any person in or on a motor vehicle in transport. Includes the driver, passengers, and persons riding on the exterior of a motor vehicle (e.g., a skateboard rider holding onto a moving vehicle). Excludes occupants of parked cars unless they are double parked or motionless on the roadway.
Occupational Fatality	Death resulting from a job-related injury.
Occupational Illness	Any abnormal condition or disorder caused by environmental factors associated with a worker's employment, but not the result of an injury. (FRA3)
Occupied Caboose	A rail car being used to transport non-passenger personnel. (49CFR171)
Ocean Bill of Lading	A receipt for the cargo and a contract for transportation between a shipper and the ocean carrier. It may also be used as an instrument of ownership which can be bought, sold, or traded while the goods are in transit. (USTTA1)
Ocean Freight Differential (OFD)	The amount by which the cost of the ocean freight bill for the portion of commodities required to be carried on U.S. flag vessels exceeds the cost of carrying the same amount on foreign flag vessels. When applied to agricultural commodities shipped under Food for Peace, OFD is the amount paid by the Commodity Credit Corporation. (USTTA1)
Ocean Going Container	Usually made of steel, it is a large rectangular box designed for easy lift on/off by cranes. (BOC3)
Oceanic Airspace	Airspace over the oceans of the world, considered international airspace, where oceanic separation and procedures per the International Civil Aviation Organization are applied. Responsibility for the provisions of air traffic control service in this airspace is delegated to various countries, based generally upon geographic proximity and the availability of the required resources. (FAA4)
Oceanic Display and Planning System	An automated digital display system which provides flight data processing, conflict probe, and situation display for oceanic air traffic control. (FAA4)
Oceanic Navigational Error Report (ONER)	A report filed when an aircraft exiting oceanic airspace has been observed by radar to be off course. ONER reporting parameters and procedures are contained in Order 7110.82, Monitoring of Navigational Performance In Oceanic Areas. (FAA4)
Oceanic Published Route	A route established in international airspace and charted or described in flight information publications, such as Route Charts, Department of Defense (DOD) En Route Charts, Chart Supplements, NOTAM's, and Track Messages. (FAA4)
Oceanic Transition Route	Route established for the purpose of transitioning aircraft to/from an organized track system. (FAA4)
Off Course	(See also On Course, On-Course Indication) A term used to describe a situation where an aircraft has reported a position fix or is observed on radar at a point not on the air traffic control (ATC) approved route of flight. (FAA4)
Off Route Vector	A vector by Air Traffic Control (ATC) which takes an aircraft off a previously assigned route. Altitudes assigned by ATC during such vectors provide required obstacle clearance. (FAA4)
Office of Management and Budget (OMB)	OMB's predominant mission is to assist the President in overseeing the preparation of the federal budget and to supervise its administration in Executive Branch agencies. In helping to formulate the President's spending plans, OMB evaluates the effectiveness of agency programs, policies, and procedures, assesses competing funding demands among agencies, and sets funding priorities. OMB ensures that agency reports, rules, testimony, and proposed legislation are consistent with the President's Budget and with Administration policies. In addition, OMB oversees and coordinates the Administration's procurement, financial management, information, and regulatory policies. In each of these areas, OMB's role is to help improve administrative management, to develop better performance measures and coordinating mechanisms, and to reduce any unnecessary burdens on the public.
Office of the Secretary of Transportation (OST)	The Department of Transportation is administered by the Secretary of Transportation, who is the principal adviser to the President in all matters relating to Federal transportation programs. The Secretary is assisted in the administration of the Department by a Deputy Secretary of Transportation, a Associate Deputy Secretary, the Assistant Secretaries, a General Counsel, the Inspector General, and several Directors and Chairmen. (OFR1)
Officer In Charge Marine Inspection (OCMI)	A person from the civilian or military branch of the Coast Guard designated as such by the Commandant and who under the supervision and direction of the Coast Guard District Commander is in charge of a designated inspection zone for the performance of duties with respect to the enforcement and administration of Title 52, Revised Statutes, acts amendatory thereof or supplemental thereto, rules and regulations thereunder, and the inspection required thereby. (49CFR171)
Off-Road Vehicular Area	An area for the testing of, or use by, vehicles that are designed to travel across the terrain. (DOI4)
Offset Parallel Runway	Staggered runways having centerlines which are parallel. (FAA4)
Offshore	That geographic area that lies seaward of the coastline. In general, the coastline is the line of ordinary low water along with that portion of the coast that is in direct contact with the open sea or the line marking the seaward limit of inland water. (49CFR195) (DOE3) (DOE5)
Offshore Control Area	That portion of airspace between the U.S 12-mile limit and the Oceanic Control Area/Flight Information Region (CTA/FIR) boundary within which air traffic control is exercised. These areas are established to permit the application of domestic procedures in the provision of air traffic control services. Offshore Control Area is generally synonymous with Federal Aviation Regulations, Part 71, Subpart E, "Control Areas and Control Area Extensions." (FAA4)
Offshore Supply Vessel	A cargo vessel of less than 500 gross tons that regularly transports goods, supplies or equipment in support of exploration or production of offshore mineral or energy resources. (49CFR171)
Oil	A mixture of hydrocarbons usually existing in the liquid state in natural underground pools or reservoirs. Gas is often found in association with oil. (DOE5)
Oil and Gas Production	The lifting of oil and gas to the surface and gathering, treating, field processing (as in the case of processing gas to extract liquid hydrocarbons), and field storage. The production function shall normally be regarded as terminating at the outlet valve on the lease or field production storage tank. If unusual physical or operational circumstances exist, it may be more appropriate to regard the production function as terminating at the first point at which oil, gas, or gas liquids are delivered to a main pipeline, a common carrier, a refinery, or a marine terminal. (DOE5)
Oil Field Body	Heavily constructed platform-type truck body equipped with instruments for oil drilling. (ATA1)
Oil Pipeline Mode	(See also Pipeline) Covers crude oil, petroleum product and gas trunk lines. The pipeline industry, which transports oil and petroleum products, is an important if specialized freight mode. (BTS1)
Oil Spill Removal Organization	An entity that provides response resources. (49CFR194)
Omega	An Area Navigation (RNAV) system designed for long-range navigation based upon ground-based electronic navigational aid signals. (FAA4)
On a Stand	River stationary as to rise or fall. (TNDOT1)
On Course	(See also Off Course, On-Course Indication) 1) Used to indicate that an aircraft is established on the route centerline. 2) Used by Air Traffic Control (ATC) to advise a pilot making a radar approach that his aircraft is lined up on the final approach course. (FAA4)
On Dock Rail	Direct shipside rail service. Includes the ability to load and unload containers/ breakbulk directly from rail car to vessel.
On Flight Passenger Trip Length	The average length of a passenger trip, calculated by dividing the number of revenue passenger-miles in scheduled service by the number of revenue passenger enplanements in scheduled service. (BTS5) (BTS6)
On-Course Indication	(See also Off Course, On Course) An indication on an instrument, which provides the pilot a visual means of determining that the aircraft is located on the centerline of a given navigational track, or an indication on a radar scope that an aircraft is on a given track. (FAA4)
On-Road Mile Per Gallon (MPG)	A composite miles per gallon (MPG) that was adjusted to account for the difference between the test value and the fuel efficiency actually obtained on the road. (DOE4)
Onshore Oil Pipeline Facilities	New and existing pipe, rights-of-way and any equipment, facility, or building used in the transportation of oil located in, on, or under, any land within the United States other than submerged land. (49CFR194)
On-System	Any point on or directly interconnected with a transportation, storage, or distribution system operated by a natural gas company. (DOE5)
On-Time Performance	The proportion of the time that a transit system adheres to its published schedule times within state tolerances. (TRB1)
On-Track Equipment	Railroad rolling stock used to transport freight or passengers; includes locomotives, railroad cars, maintenance equipment, and one or more locomotives coupled to one or more cars. (FRA3)
Open Channel	That portion of the river above pool water. (TNDOT1)
Open Cut	Rail transit way below surface in an excavated cut that has not had a covering constructed over it. Transition segments to open cut or subway-tunnel/tube segments are included. (FTA1)
Open Insurance Policy	A marine insurance policy that applies on all shipments over a period of time rather than on a single shipment. (TNDOT1)
Open Motorboat	Craft of open construction specifically built for operating with a motor, including boats canopied or fitted with temporary partial shelters. (USCG2)
Open River	1) Any river having no obstructions such as dams; 2) When the stage of a pooled river running through movable dams is high enough for traffic to clear the dams, the river is said to be "open". (TNDOT1)
Open to Public Travel Road	A road must be available, except during scheduled periods, extreme weather or other emergency conditions, and open to the general public for use by four-wheel, standard passenger cars without restrictive gates, prohibitive signs, or regulation other than restrictions based on size, weight, or class of registration. Toll plazas of public toll facilities are not considered restrictive gates. (23CFR460) (FHWA2)
Open Top	Trailer with sides but without permanent top; often used for heavy equipment that must be lowered into place by crane. (ATA1)
Open-Access Transportation	The contract carriage delivery of nonsystem supply gas on a nondiscriminatory basis for a fee generally subject to transportation tariffs which are usually on an interruptible service basis on first-come, first-serve capacity usage. (DOE1)
Open-Body Type Vehicle	A vehicle having no occupant compartment top or an occupant compartment top that can be installed or removed by the user at his convenience. (49CFR571)
Operate	With respect to aircraft, means use, cause to use or authorize to use aircraft, for the purpose (except as provided in 14 CFR 91.13) of air navigation including the piloting of aircraft, with or without the right of legal control (as owner, lessee, or otherwise). (14CFR1)
Operating Assistance	Financial assistance for transit operations (not capital expenditures). Such aid may originate with federal, local, or state governments. (APTA1)
Operating Cost	1) Fixed operating cost in reference to passenger car operating cost, refers to those expenditures that are independent of the amount of use of the car, such as insurance costs, fees for license and registration, depreciation and finance charges; 2) Variable operating cost in reference to passenger car operating cost, expenditures which are dependent on the amount of use of the car, such as the cost of gas and oil, tires, and other maintenance. (DOE6)
Operating Employee	An employee involved with operation, maintenance, or administration of the transit system, excluding those involved in construction and capital procurement. (APTA1)
Operating Expenses	Expenses incurred in the performance of air transportation, based on overall operating revenues and overall operating expenses. Does not include nonoperating income and expenses, nonrecurring items or income taxes. (BTS4)
Operating Expenses (Air)	Expenses incurred in the performance of air transportation, based on overall operating revenues and expenses. Does not include nonoperating income and expenses, nonrecurring items, or income taxes.
Operating Expenses (Rail)	Expenses of furnishing transportation services, including maintenance and depreciation of the plant used in the service.
Operating Expenses (Transit)	The total of all expenses associated with operation of an individual mode by a given operator. Includes distributions of “joint expenses” to individual modes and excludes “reconciling items,” such as interest expenses and depreciation. Should not be confused with “vehicle operating expenses.”
Operating Expenses (Truck)	Includes expenditures for equipment maintenance, supervision, wages, fuel, equipment rental, terminal operations, insurance, safety, and administrative and general functions.
Operating Practice	Railroad employment performance and adherence to the established operating rules of a railroad company. (FRA3)
Operating Profit or Loss	Profit or loss from performance of air transportation, based on overall operating revenues and overall operating expenses. Does not include nonoperating income and expenses, nonrecurring items or income taxes. (BTS4)
Operating Property and Equipment	Owned assets including capital leases and leaseholds which are used and useful to the air carrier's central business activity, excluding those assets held for resale, or inoperative or redundant to the air carrier's current operations. These assets include loans and units of tangible property and equipment that are used in air transportation services and services incidental thereto. (BTS4)
Operating Ratio	The ratio of operating expenses to operating revenues. (AAR1)
Operating Revenue	Revenues from the performance of air transportation and related incidental services. Includes 1) Transport revenues from the carriage of all classes of traffic in scheduled and nonscheduled services and 2) Nontransport revenues consisting of Federal subsidy (where applicable) and revenues for services related to air transportation. (BTS4)
Operating Revenues (Air)	Revenues from the performance of air transportation and related incidental services. Includes l) transportation revenues from the carriage of all classes of traffic in scheduled and nonscheduled services, and 2) nontransportation revenues consisting of federal subsidies (where applicable) and services related to air transportation.
Operation of a Railroad	Inclusive term used to describe all activities of a railroad related to the performance of its rail transportation business. (FRA2)
Operational Acceptable Level of Traffic (OALT)	An air traffic activity level associated with the designed capacity for a sector or airport. The OALT considers dynamic changes in staffing, personnel experience levels, equipment outages, operational configurations, weather, traffic complexity, aircraft performance mixtures, transitioning flights, adjacent airspace, handoff/point-out responsibilities, and other factors that may affect an air traffic operational position or system element. The OALT is normally considered to be the total number of aircraft that any air traffic functional position can accommodate for a defined period of time under a given set of circumstances. (FAA4)
Operational Control	With respect to a flight, means the exercise of authority over initiating, conducting or terminating a flight. (14CFR1)
Operational Deviation	(See also Operational Error, Pilot Deviation, Runway Incursion, Vehicle/Pedestrian Deviation) An occurrence where applicable separation minima as referenced in the operational error definition below were maintained but 1) Less than the applicable separat
Operational Error	(See also Operational Deviation, Pilot Deviation, Runway Incursion, Vehicle/Pedestrian Deviation) An occurrence attributable to an element of the air traffic control system which 1) results in less than the applicable separation minima between two or more aircraft, or between an aircraft and terrain or obstacles and obstructions as required by Handbook 7110.65 and supplemental instructions. Obstacles include vehicles/equipment on runways; 2) aircraft lands or departs on a runway closed to aircraft operations after receiving air traffic authorization. (FAA3)
Operational Road	Usable road and intended for use. (DOI3)
Operational Runway	Usable and intended for use runway. (DOI3)
Operator	A person who controls the use of an aircraft, vessel, or vehicle. (49CFR171)
Operators	The personnel (other than security agents) scheduled to be aboard vehicles in revenue operations including vehicle operators, conductors and ticket collectors. (FTA1)
Opposing Signals	Roadway signals which govern movements in opposite directions on the same track. (49CFR236)
Opposing Train	A train, the movement of which is in a direction opposite to and toward another train on the same track. (49CFR236)
Opposite Direction Aircraft	Aircraft are operating in opposite directions when 1) They are following the same track in reciprocal directions; or 2) Their tracks are parallel and the aircraft are flying in reciprocal directions; or 3) Their tracks intersect at an angle of more than 136 degrees. (FAA4)
Option Approach	See Cleared for the Option.
Ordinary High Water Line	In nature, that water elevation below which aquatic vegetation will not grow. In practice, a water surface elevation arbitrarily fixed from past experience or the establishment of navigation pools. (TNDOT1)
Organized Track System	A movable system of oceanic tracks that traverses the North Atlantic between Europe and North America the physical position of which is determined twice daily taking the best advantage of the winds aloft. (FAA4)
Origin	Starting point of a trip. (FHWA3)
Originated Carload	An originated carload is one which is loaded and begins its journey on a particular railroad. (AAR1)
Other 2-Axle 4-Tire Vehicles (Truck)	Includes vans, pickup trucks, and sport utility vehicles.
Other Assets	Debit balances in general clearing accounts including prepayments chargeable against operations over a period of years, capitalized expenditures of an organization or developmental character, long-term prepayments, and property acquisition adjustments. (BTS4)
Other Deferred Credits	Credit balances in general clearing accounts including credits for which the final disposition cannot be effected until additional information has been received. (BTS4)
Other Freeways and Expressways	All urban principal arterials with limited control of access not on the Interstate system. (NHTSA3)
Other Freeways And Expressways (Highway)	All urban principal arterials with limited access but not part of the Interstate system.
Other Interest Expense	Interest expense other than that on long-term debt and capital leases. This includes interest expense on short-term debt, imputed interest capitalized, and amortization of premium on all classes of debt. (BTS4)
Other Nonoperating Income and Expenses, Net	Income from investor controlled companies and nontransport ventures, equipment and investments in securities of others, interest income, gains or losses resulting from nonroutine abnormal changes in the rates of foreign exchange, and other nonoperating items except capital gains or losses and interest expense. (BTS4)
Other Principal Arterials (Highway)	Major streets or highways, many of multi-lane or freeway design, serving high-volume traffic corridor movements that connect major generators of travel.
Other Rail Revenue	Includes revenues from miscellaneous operations (i.e., dining- and bar-car services), income from the lease of road and equipment, miscellaneous rental income, income from nonoperating property, profit from separately operated properties, dividend income, interest income, income from sinking and other reserve funds, release or premium on funded debt, contributions from other companies, and other miscellaneous income.
Other Revenue Vehicles (Transit)	Other revenue-generating modes of transit service, such as cable cars, personal rapid transit systems, monorail vehicles, inclined and railway cars, not covered otherwise.
Other Single-Unit Truck	A motor vehicle consisting primarily of a single motorized device with more than two axles or more than four tires. (DOE6)
Other Tanker Vessel	A crude oil carrying ship of between 25,000 and 160,000 deadweight tons. (DOE5)
Other Transport Related Revenue	Revenues from services such as in-flight sales, rentals and sales of services, supplies and parts. (BTS4)
Other Truck	All trucks other than pickups, (i.e., dump trucks, trailer trucks, etc.). (FHWA3)
Other Vehicle	Consists of the following types of vehicles 1) Large limousines (more than four side doors or stretched chassis), 2) Three-wheel automobiles or automobile derivatives, 3) Van-based motor homes, 4) Light-truck-based motor homes (chassis mounted), 5) Large-truck-based motor homes, 6) ATVs (all terrain vehicle, including dune/swamp buggy) and ATC (all terrain cycle), 7) Snowmobiles, 8) Farm equipment other than trucks, 9) Construction equipment other than trucks (includes graders), 10) Other type vehicles (includes go-cart, fork lift, city streetsweeper). (NHTSA3)
Out	The conversation is ended and no response is expected. (FAA4)
Out Draft	Current moving across the lock entrance toward the river or toward the dam. (TNDOT1)
Out of Shape	Term used when a tow is not in the proper position to negotiate the channel or to shove into, or come out of, a lock (conversely, "in shape"). (TNDOT1)
Out Riggers	Device used for increasing width of trailers. (ATA1)
Out Wide, Just Below	Channel report term meaning after passing the mark, swing out wide away from the bank. (TNDOT1)
Outage	The loss of a facility/service for one minute or more. (FAA3)
Outage (or Ullage)	The amount by which a packaging falls short of being liquid full, usually expressed in percent by volume. (49CFR171)
Outboard	An engine not permanently affixed to the structure of the craft, regardless of the method or location used to mount the engine, (e.g., motor wells, "kicker pits", motor pockets, etc). (USCG2)
Outboard Designated Seating Position	A designated seating position where a longitudinal vertical plane tangent to the outboard side of the seat cushion is less than 12 inches from the innermost point on the inside surface of the vehicle at a height between the design H-point and the shoulder reference point and longitudinally between the front and rear edges of the seat cushion. (49CFR571)
Outer Area	Nonregulatory airspace surrounding designated Class C airspace airports wherein Air Traffic Control (ATC) provides radar vectoring and sequencing on a full-time basis for all Instrument Flight Rules (IFR) and participating Visual Flight Rules (VFR) aircraft. The service provided in the outer area is called Class C service which includes IFR/IFR-standard Instrument Flight Rules separation; IFR/VFR-traffic advisories and conflict resolution; and VFR/VFR-traffic advisories and, as appropriate, safety alerts. The normal radius will be 20 nautical miles with some variations based on site-specific requirements. The outer area extends outward from the primary Class C airspace airport and extends from the lower limits of radar/ radio coverage up to the ceiling of the approach control's delegated airspace excluding the Class C charted area and other airspace as appropriate. (FAA4)
Outer Compass Locator (OCL)	A compass locator installed at the site of the outer marker of an instrument landing system. (FAA4)
Outer Continental Shelf	Offshore Federal domain. (DOE5)
Outer Fix	A general term used within Air Traffic Control (ATC) to describe fixes in the terminal area, other than the final approach fix. Aircraft are normally cleared to these fixes by an Air Route Traffic Control Center or an Approach Control Facility. Aircraft are normally cleared from these fixes to the final approach fix or final approach course. (FAA4)
Outer Fix Time	A calculated time to depart the outer fix in order to cross the vertex at the actual calculated landing time. The time reflects descent speed adjustments and any applicable delay time that must be absorbed prior to crossing the meter fix. (FAA4)
Outer Lock Wall	The wall of the lock on the river or channel side away from the shore. (TNDOT1)
Outer Marker (OM)	(See also Compass Locator, Glideslope, Instrument Landing System, Localizer, Middle Marker) A marker beacon at or near the glideslope intercept altitude of an Instrument Landing System (ILS) approach. It is keyed to transmit two dashes per second on a 400 Hz tone, which is received aurally and visually by compatible airborne equipment. The OM is normally located four to seven miles from the runway threshold on the extended centerline of the runway. (FAA4)
Outer Packaging	The outermost enclosure of a composite or combination packaging together with any absorbent materials, cushioning and any other components necessary to contain and protect inner receptacles or inner packagings. (49CFR171)
Outlays	Actual cash (or electronic transfer) payments made to the States or other entities. Outlays are provided as reimbursement for the Federal share for approved highway program activities.
Output	The amount of power or energy produced by a generating unit, station, or system. (DOE5)
Outside of a Bend	The side of the river channel with the largest projected circumference. (TNDOT1)
Over	My transmission is ended; I expect a response. (FAA4)
Overall (Ton Miles, Load Factor, Available Capacity, Etc.)	The total of passenger plus nonpassenger traffic, i.e., the sum of passenger and baggage, freight, express, U.S. mail, and foreign mail. (BTS5)
Overall Available Ton Mile	The aircraft miles flown on each inter-airport hop multiplied by the capacity available (in tons) for that hop for revenue traffic use. (BTS5)
Overall Flight Stage Length	The average distance covered per aircraft hop in revenue services, from take-off to landing. Derived by dividing the total aircraft miles flown in revenue service by the number of aircraft revenue departures performed. (BTS5)
Overall Revenue Ton Mile	The aircraft miles flown on each inter-airport hop multiplied by the tons of revenue traffic (passenger and nonpassenger) carried on that hop. (BTS5)
Overall Vehicle Width	The nominal design dimension of the widest part of the vehicle, exclusive of signal lamps, marker lamps, outside rearview mirrors, flexible fender extensions. and mud flaps, determined with doors and windows closed and the wheels in the straight-ahead position. (49CFR571)
Overfalls	Short breaking waves occurring when a current passes over a shoal or other submarine obstruction or meets a contrary current or wind. (DOI4)
Overhead Maneuver	A series of predetermined maneuvers prescribed for aircraft (often in formation) for entry into the visual flight rules (VFR) traffic pattern and to proceed to a landing. An overhead maneuver is not an instrument flight rules (IFR) approach procedure. An aircraft executing an overhead maneuver is considered VFR and the IFR flight plan is cancelled when the aircraft reaches the "initial point" on the initial approach portion of the maneuver. The pattern usually specifies the following 1) The radio contact required of the pilot. 2) The speed to be maintained. 3) An initial approach 3 to 6 miles in length. 4) An elliptical pattern consisting of two 180 degree turns. 5) A break point at which the first 180 degree turn is started. 6) The direction of turns. 7) Altitude (at least 600 feet above the conventional pattern). 8) A "Roll-out" on final approach not less than 1/4 mile from the landing threshold and not less than 300 feet above the ground. (FAA4)
Overload	Using all available power. (TNDOT1)
Overloading	Excessive loading of the vessel causing instability, limited maneuverability, dangerously reduced freeboard, etc. (USCG2)
Overlook Access	(See also Public Use Class II Road) A road that provides access to a pull-off area, having definite entrance and exit points. (DOI3)
Overlying Center	The Air Route Traffic Control Center (ARTCC) facility that is responsible for arrival/departure operations at a specific terminal. (FAA4)
Overpack	An enclosure that is used by a single consignor to provide protection or convenience in handling of a package or to consolidate two or more packages. Overpack does not include a freight container. (49CFR171)
Overrun/Stopway	An area beyond the take off runway able to support an airplane during an aborted take off. (DOI4)
Overseas	Transit to or from foreign ports beyond the Coast of Canada and the United States. (SLSDC1)
Overseas Air Commerce	The carriage by aircraft of persons or property for compensation or hire, or the carriage of mail by aircraft, or the operation or navigation of aircraft in the conduct or furtherance of a business or vocation, in commerce between a place in any state of the United States, or the District of Columbia and any place in a territory or Possession of the United States; or between a place in a territory or possession of the United States, and a place in any other territory or possession of the United States. (14CFR1)
Overseas Air Transportation	The carriage by aircraft of persons or property as a common carrier for compensation or hire, or the carriage of mail by aircraft, in commerce 1) Between a place in a state or the District of Columbia and a place in a possession of the United States; or 2) Between a place in a possession of the United States and a place in another possession of the United States whether that commerce moves wholly by aircraft or partly by aircraft and partly by other forms of transportation. (14CFR1)
Over-The-Road Bus	A bus characterized by an elevated passenger deck located over a baggage compartment. (49CFR37)
Over-The-Road Trip	An intercity movement by commercial motor vehicle. (FHWA4)
Over-The-Top	Above the layer of clouds or other obscuring phenomena forming the ceiling. (14CFR1)
Own Source Revenue	All amounts of money received by a government from external sources, net of refunds and other correcting transactions, other than from the issuance of debt, liquidation of investments, and as agency and private trust transactions. The federal government's revenues are generally referred to as receipts. (BTS3)
Owner operator	Trucking operation in which the owner of the truck is also the driver.
Owner/Operator	Independent trucker who drives the vehicle for himself or on lease to a company. (BOC4)
Owning Agency	A federal agency having accountability for government owned motor vehicles. This term applies when a federal agency has authority to take possession of, assign or reassign the vehicle regardless of which agency is using the vehicle. (GSA1)
Oxbow Lakes	Lakes resulting from the cutting off of sharp river bends during realignment of a river channel. (TNDOT1)
Oxygenate	A substance which, when added to gasoline, increases the amount of oxygen in that gasoline blend. Includes fuel ethanol, methanol, and methyl tertiary butyl ether (MTBE). (DOE6)
Oxygenated gasoline	Gasoline enriched with oxygen bearing liquids to reduce CO production by permitting more complete combustion.
Oxygenated Motor Gasoline	(See also Fuel, Gasohol, Gasoline, Motor Gasoline, Kerosene) Motor gasoline, formulated for use in motor vehicles, that has an oxygen content of 1.8 percent or higher by weight. (DOE3)
Oxygenates	Any substance that when added to motor gasoline increases the amount of oxygen in that gasoline blend. Includes oxygen-bearing compounds such as ethanol, methanol, and methyl-tertiary-butyl-ether. Oxygenated fuel tends to give a more complete combustion of carbon into carbon dioxide (rather than monoxide), thereby reducing air pollution from exhaust emissions.
Ozone 03	Ozone is a colorless gas with a sweet odor. Ozone is not a direct emission from transportation sources. It is a secondary pollutant formed when VOCs and NOx combine in the presence of sunlight. Ozone is associated with smog or haze conditions. Although the ozone in the upper atmosphere protects us from harmful ultraviolet rays, ground-level ozone produces an unhealthy environment in which to live. Ozone is created by human and natural sources.
P & D's	Pick up and deliveries of freight. (ATA1)
P.L. 93-638 - Indian Self-Determination and Education Assistance Act, as amended	The response by Congress, in recognition of the unique obligation of the United States, to the strong expression of the Indian people for self-determination, assuring maximum Indian participation in the direction of education as well as other Federal services for Indian communities so as to render such programs and services more responsive to the needs and desires of Indian communities.
P.M. Peak Period	(See also A.M. Peak Period) The period in the afternoon or evening when additional services are provided to handle higher passenger volumes. The period begins when normal headways are reduced and ends when headways are returned to normal. (FTA1)
Package Freight	In the historical tables, designates cargo consisting of miscellaneous packages generally unidentifiable as to commodity and carried only on vessels licensed by the respective Authorities in Canada and the United States. This commodity classification is no longer applicable. (SLSDC1)
Packaging	A receptacle and any other components or materials necessary for the receptacle to perform its containment function in conformance with the minimum packing requirements of 49CFR, Chapter I, Subchapter C. (49CFR171)
Packet	A boat, usually a coastal or river steamer, that plies a regular route, carrying passengers, freight, and mail. (TNDOT1)
Packing and Crating	Establishments primarily engaged in packing, crating, and otherwise preparing goods for shipping. (BOC1)
Packing Group	A grouping according to the degree of danger presented by hazardous materials. Packing Group I indicates great danger; Packing Group II, medium danger; Packing Group III, minor danger. (49CFR171)
Paid Storage	A vehicle on assignment to a customer agency but temporarily out of service (usually a seasonally used vehicle). (GSA2)
Paid-In Capital	Invested capital from stock subscribed or issued at a par or stated value (or the subscription value in the case of stock without par value) for preferred stock and common stock. (BTS4)
Pajama Wagon	Sleeper tractor. (ATA1)
Pallet	A platform with or without sides, on which a number of packages or pieces may be loaded to facilitate handling by a lift truck. (MARAD2)
Pan Pan	(See also May Day) The international radio-telephony urgency signal. When repeated three times, indicates uncertainty or alert followed by the nature of the urgency. (FAA4)
Pancake	Brake diaphragm housing. (ATA1)
Panel Body	Small, fully enclosed truck body often used for small package delivery. (ATA1)
Parachute	A device used or intended to be used to retard the fall of a body or object through the air. (14CFR1)
Parallel ILS Approaches	Approaches to parallel runways by Instrument Flight Rules (IFR) aircraft which, when established inbound toward the airport on the adjacent final approach courses, are radar separated by at least 2 miles. (FAA4)
Parallel Offset Route	A parallel track to the left or right of the designated or established airway/route. Normally associated with Area Navigation (RNAV) operations. (FAA4)
Parallel Runway	Two or more runways at the same airport whose centerlines are parallel. In addition to runway numbers, parallel runways are designated as L (left) and R (right) or, if three parallel runways exist, L (left), C (center), and R (right). (FAA4)
Paratransit	1) Comparable transportation service required by the American Disabilities Act (ADA) for individuals with disabilities who are unable to use fixed route transportation systems. (49CFR37) (APTA1) 2) A variety of smaller, often flexibly scheduled-and-routed transportation services using low-capacity vehicles, such as vans, to operate within normal urban transit corridors or rural areas. These services usually serve the needs of persons that standard mass-transit services would serve with difficulty, or not at all. Often, the patrons include the elderly and persons with disabilities.
Park	A place or area set aside for recreation or preservation of a cultural or natural resource. (DOI4)
Park and Ride	An access mode to transit in which patrons drive private automobiles or ride bicycles to a transit station, stop, or carpool/vanpool waiting area and park the vehicle in the area provided for the purpose. They then ride the transit system or take a car-or vanpool to their destinations. (TRB1)
Park and Ride Lot	Designated parking area for automobile drivers who then board transit vehicles from these locations. (APTA1)
Parking Area	An area set aside for the parking of motor vehicles. (DOI4)
Parking Brake	A mechanism designed to prevent the movement of a stationary motor vehicle. (49CFR571)
Parking Brake System	A brake system used to hold a vehicle stationary. (49CFR393)
Parkway	A highway that has full or partial access control, is usually located within a park or a ribbon of park-like developments, and prohibits commercial vehicles. Buses are not considered commercial vehicles in this case. (FHWA2)
Participating Agency	A federal department or agency which transferred (consolidated) vehicles to the Interagency Fleet Management System (IFMS). (GSA2)
Particulate Matter (PM10 and PM2.5)	Particulate matter consists of airborne solid particles and liquid droplets. Particulate matter may be in the form of fly ash, soot, dust, fog, fumes, etc. These particles are classified as "coarse" if they are smaller than 10 microns, or "fine" if they are smaller than 2.5 microns. Coarse airborne particles are produced during grinding operations, or from the physical disturbance of dust by natural air turbulence processes, such as wind. Fine particles can be a by-product of fossil fuel combustion, such as diesel and bus engines. Fine particles can easily reach remote lung areas, and their presence in the lungs is linked to serious respiratory ailments such as asthma, chronic bronchitis and aggravated coughing. Exposure to these particles may aggravate other medical conditions such as heart disease and emphysema and may cause premature death. In the environment, particulate matter contributes to diminished visibility and particle deposition (soiling).
Particulate Matter Emissions (PM)	Particulate matter (PM) is the general term used for a mixture of solid particles and liquid droplets founclin the air. They originate from many differ­ent stationary and mobile sources as well as from natural sources, including fuel combustion from motor vehicles, power generation, and industrial facilities, as well as from residential fire­places and wood stoves. Fine particles are most closely associated with such health effects as increased hospital admissions and emergency room visits for heart and lung disease, increased respiratory symptoms and disease, decreased lung function, and even premature death.
Particulates	Carbon particles formed by partial oxidation and reduction of the hydrocarbon fuel. Also included are trace quantities of metal oxides and nitrides, originating from engine wear, component degradation, and inorganic fuel additives. In the transportation sector, particulates are emitted mainly from diesel engines. (DOE6)
Parts Per Million (PPM)	A measure of air pollutant concentrations.
Pass	Any one of several distributary channels near the mouth of the Mississippi River. (TNDOT1)
Pass Cells	Piers on each side of the navigable pass of a dam. (TNDOT1)
Pass Sill Gage	Gage indicating depth through navigable pass. (TNDOT1)
Passenger	A person who is on, boarding, or alighting from a railroad car for the purpose of travel, without participating in its operation. (FRA3)
Passenger Automobile	A passenger automobile is any automobile (other than an automobile capable of off-highway operation) manufactured primarily for use in the transportation of not more than 10 individuals. (49CFR523)
Passenger Car	A motor vehicle designed primarily for carrying passengers on ordinary roads, includes convertibles, sedans, and stations wagons.
Passenger Car Equivalence	The representation of larger vehicles, such as buses, as equal to a quantity of automobiles (passenger cars) for use in level of service and capacity analyses. (TRB1)
Passenger Count	A count of the passengers on a vehicle or who use a particular facility. (TRB1)
Passenger Enplanements	The total number of passengers boarding an aircraft. (BTS6)
Passenger Facility Charge (PFC)	(See also Apportionment) Public agencies controlling a commercial service airport can charge enplaning passengers using the airport a $1, $2, or $3 facility charge. Public agencies must apply to the FAA and meet certain requirements in order to impose a PFC. (FAA11)
Passenger Flow	The number of passengers who pass a given location in a specified direction during a given period. (TRB1)
Passenger Load Factor	The percent that revenue passenger miles are of available seat-miles in revenue passenger services, representing the proportion of aircraft seating capacity that is actually sold and utilized. (BTS6) (FAA11)
Passenger Mile	1) One passenger transported one mile. Total passenger miles are computed by summation of the products of the aircraft miles flown on each inter-airport flight stage multiplied by the number of passengers carried on that flight stage. (AIA1) (FAA11) (NTSB1) 2) The cumulative sum of the distances ridden by each passenger. (FTA1)
Passenger Per Aircraft Mile	The average number of passengers carried per aircraft in revenue passenger services, derived by dividing the total revenue passenger-miles by the total aircraft miles flown in revenue passenger services. (BTS6)
Passenger Revenue	1) Rail Revenue from the sale of tickets. 2) Air Revenues from the transport of passengers by air. 3) Transit Fares, transfer, zone, and park-an
Passenger Revenue Ton Mile	One ton of revenue passenger weight (including all baggage) transported one mile. The passenger weight standard for both domestic and international operations is 200 pounds. (BTS5) (BTS6)
Passenger Service	Both intercity rail passenger service and commuter rail passenger service. (49CFR245)
Passenger Service Expenses	Costs of activities contributing to comfort, safety, and convenience of passengers while in flight and when flights are interrupted. Includes salaries and expenses of flight attendants and passenger food expenses. (BTS4)
Passenger Vehicle	A vehicle with a Gross Vehicle Weight Rating (GVWR) of 10,000 pounds or less which includes passenger cars, light pickup trucks, light vans, and utility vehicles. (NHTSA4)
Passenger Vehicle Crash	A motor vehicle crash involving at least one passenger vehicle. (NHTSA4)
Passenger Vessel	1) A vessel subject to any of the requirements of the International Convention for the Safety of Life at Sea, 1974, which carries more than 12 passengers; 2) A cargo vessel documented under the laws of the United States and not subject to that Convention, which carries more than 16 passengers; 3) A cargo vessel of any foreign nation that extends reciprocal privileges and is not subject to that Convention and which carries more than 16 passengers; and 4) A vessel engaged in a ferry operation and which carries passengers. (49CFR171)
Passenger Vessels (Water)	A vessel designed for the commercial transport of passengers.
Passenger-Carrying Aircraft	An aircraft that carries any person other than a crewmember, company employee, an authorized representative of the United States, or a person accompanying the shipment. (49CFR171)
Passenger-Carrying Volume	The sum of the front seat volume and, if any, rear seat volume, as defined in 40 CFR 600.315, in the case of automobiles to which that term applies. With respect to automobiles to which that term does not apply, "passenger-carrying volume" means the sum in cubic feet, rounded to the nearest 0.1 cubic feet, of the volume of a vehicle's front seat and seats to the rear of the front seat, as applicable, calculated in 49 CFR 523.2 with the head room, shoulder room, and leg room dimensions determined in accordance with the procedures outlined in Society of Automotive Engineers (SAE) Recommended Practice J1100a, Motor Vehicle Dimensions (Report of Human Factors Engineering Committee, Society of Automotive Engineers, approved September 1973 and last revised September 1975). (49CFR523)
Passenger-Miles	One passenger transported 1 mile. Passenger miles are computed by the summation of the products of the aircraft-miles flown on each inter-airport flight multiplied by the number of passengers carried on the flight. (DOE6)
Passenger-Miles Traveled (PMT)	One person traveling the distance of one mile. Total passenger-miles traveled by all persons. (DOE6)
Passengers On Trains (Class C)	Persons who are on, boarding, or alighting from railroad cars for the purpose of travel. (FRA2)
Passing Daymark	A rectangular or triangular daymark used on lights which are intended for position reference only and are not to be steered on. (TNDOT1)
Pass-Through Funds	Operating financial assistance passed through to other transit agencies that have no relationship to the directly operated and/or purchased transportation services provided by the designated recipient. (FTA1)
Patron	A person who intends to use or has used the transit system and is on property affiliated with the transit system. An employee is not a patron. (FTA1)
Paved Road Surface	Bituminous, concrete, brick, block, and other special surfaces. (FHWA2)
Paved Surface	Surface of asphalt or concrete. (DOI3)
Pavement Management System	A systematic process that provides, analyzes, and summarizes pavement information for use in selecting and implementing cost-effective pavement construction, rehabilitation, and maintenance programs. Pavement includes all road surface types including paved, gravel, and improved or unimproved earth.
Payload	The maximum load that a unit of equipment may carry within its total rated capacity. The payload is the Gross Vehicle Weight Rating (GVWR) less the tare weight or actual weight of the unloaded vehicle. (GSA2)
Peak Kilowatt	One thousand peak watts. (DOE5)
Peak Megawatt	One million peak watts. (DOE5)
Peak Period Surcharge	An extra fee required during peak periods (rush hours). (APTA1)
Peanut Wagon	Small tractor pulling a large trailer. (ATA1)
Peat	Peat consists of partially decomposed plant debris. It is considered an early stage in the development of coal. Peat is distinguished from lignite by the presence of free cellulose and a high moisture content (exceeding 70 percent). The heat content of air-dried peat (about 50 percent moisture) is about 9 million Btu per ton. Most U.S. peat is used as a soil conditioner. The first U.S. electric power plant fueled by peat began operating in Maine in 1990. (DOE5)
Pedalcycle	Vehicle propelled by human power and operated solely by pedals; excludes mopeds. (NSC1)
Pedalcyclist	A person on a vehicle that is powered solely by pedals.
Pedestrian	Any person not in or on a motor vehicle or other vehicle. Excludes people in buildings or sitting at a sidewalk cafe. The National Highway Traffic Safety Administration also uses another pedestrian category to refer to pedestrians using conveyances and people in buildings. Examples of pedestrian conveyances include skateboards, nonmotorized wheelchairs, rollerskates, sleds, and transport devices used as equipment.
Pedestrian Accident	Is any person injured or killed in a highway motor vehicle accident who is not a vehicle occupant. (FHWA2)
Pedestrian Fatality	Are the number of pedestrians fatally injured in motor vehicle accidents. (FHWA2)
Pedestrian Walkway (or Walkway)	A continuous way designated for pedestrians and separated from the through lanes for motor vehicles by space or barrier. (23CFR217)
Peg Line	A line used in locks to prevent barge movement. (TNDOT1)
Peg-Leg	Tandem tractor with only one power axle. (ATA1)
Pegs	Small, bent metal bars countersunk in lock walls and arranged in a vertical line for hooking mooring lines on. Care must be taken that lines do not get hung up on these pegs as the vessel rises or drops in the lock. (TNDOT1)
Pelvic Impact Area	That area of the door or body side panel adjacent to any outboard designated seating position which is bounded by horizontal planes 7 inches above and 4 inches below the seating reference point and vertical transverse planes 8 inches forward and 2 inches rearward of the seating reference point. (49CFR571)
Penalty	An action taken by Federal agencies when the grant recipient does not comply with provisions of the law. For the highway program the imposition of penalties, which are defined in law, may prevent a State from using or receiving its full apportionment or may force a transfer from one program to another.
Peninsula	A body of land jutting out into and nearly surrounded by water. (DOI4)
People Mover	An automated transportation system (e.g., continuous belt system or automated guideway transit) that provides short-haul collection distribution service, usually in a major activity center. (TRB1)
Percent of Enplanement	The percent that a community's enplaned passengers is of the total enplaned passengers in all services and all operations for all communities within the 50 States, the District Columbia, and other U.S. areas designated by the Federal Aviation Administration. (FAA15)
Percent Scheduled Aircraft Miles Completed	Scheduled aircraft miles completed (excluding extra sections) as a percent of total aircraft miles scheduled. (BTS5)
Performance Measures	Indicators of how well the transportation system is performing with regard to such things as average speed, reliability of travel, and accident rates. Used as feedback in the decisionmaking process.
Perils of the Sea	Those causes of loss of goods for which the carrier is not legally liable. The elemental risks of ocean transport. (TNDOT1)
Permanent Echo	Radar signals reflected from fixed objects on the earth's surface; e.g., buildings, towers, terrain. Permanent echoes are distinguished from "ground clutter" by being definable locations rather than large areas. Under certain conditions they may be used to check radar alignment. (FAA4)
Permit Line	An imaginary line, or plane, approximately parallel to a riverbank, or shore, shoreward of which any marine structure may be erected without the authority of a formal federal navigation permit. Also called harbor line. Established by act of Congress. (TNDOT1)
Person	See also Pedestrian.
Person Miles of Travel (PMT)	A measure of person travel. When one person travels one mile, one person mile of travel results. Where 2 or more persons travel together in the same vehicle, each person makes the same number of person miles as the vehicle miles. Therefore, four persons traveling 5 miles in the same vehicle, make 4 times 5 or 20 person miles. (FHWA3)
Person Trip	A trip taken by an individual. For example, if three persons from the same household travel together, the trip is counted as one household trip and three person trips.
Personal Casualties (Boarding and Alighting Vehicle)	A non-collision incident boarding or alighting a transit agency vehicle (slips, falls, door closings, lifts) in which one or more persons are injured or die. A boarding or alighting incident must involve physical contact between the passenger and the vehicle. (FTA1)
Personal Casualties (In Stations/Bus Stops)	A non-collision incident (involving stairs, escalators, elevators, passageways, platforms) at a station or bus stop in which one or more persons are injured or die. (FTA1)
Personal Casualties (Inside Vehicle)	A non-collision incident (sudden braking, unexpected swerving) in which one or more persons within the transit vehicle are injured or die. (FTA1)
Personal Casualty (Transit)	1) An incident in which a person is hurt while getting on or off a transit vehicle (e.g., falls or door incidents), but not as a result of a collision, derailment/left roadway, or fire. 2) An incident in which a person is hurt while using a lift to get on or off a transit vehicle, but not as a result of a collision, derailment/left roadway, or fire. 3) An incident in which a person is injured on a transit vehicle, but not as a result of a collision, derailment/left roadway, or fire. 4) An incident in which a person is hurt while using a transit facility. This includes anyone on transit property (e.g., patrons, transit employees, trespassers), but does not include incidents resulting from illness or criminal activity.
Personal Casualty Associated With Escalator	An incident in which a person is hurt while using an escalator in a transit facility. Any incident in this category is included in Personal Casualty in Stations/Bus Stops. (FTA2)
Personal Casualty Associated With Lifts	An incident in which a person is hurt while using a lift to get on or off a transit vehicle. (FTA2)
Personal Casualty Entering/Exiting a Vehicle	An incident in which a person is hurt while getting on or off a transit vehicle (e.g., falls or door incidents). (FTA2)
Personal Casualty In Stations/Bus Stops	An incident in which a person is hurt while using a transit facility. This includes anyone on transit property (e.g., patrons, employees, trespassers) but does not include incidents resulting from illness or criminal activity. (FTA2)
Personal Casualty On Vehicle	An incident in which a person is injured on a transit vehicle, but not as a result of a collision, derailment/left roadway, or fire. (FTA2)
Personal Consumption Expenditure (PCE)	As used in the national accounts, the market value of purchases of goods and services by individuals and nonprofit institutions and the value of food, clothing, housing, and financial services by them as income in kind. It includes the rental value of owner-occupied houses but excludes purchase of dwellings, which are classified as capital goods (investment). (DOE6)
Personal Flotation Device (PFD)	Lifesaving device approved by the Commandant under 46 CFR 160 (i.e., life jackets). (USCG1)
Personal Flying	Any use of an aircraft for personal purposes not associated with a business or profession, and not for hire. This includes maintenance of pilot proficiency. (FAA2) (FAA9) (FAA14)
Personal Watercraft	Craft less than 13 feet in length designed to be operated by a person or persons sitting, standing or kneeling on the craft rather than within confines of a hull. (USCG2)
Person-Miles	An estimate of the aggregate distances traveled by all persons on a given trip based on the estimated transportation-network-miles traveled on that trip.
Persons Otherwise Assisted	Number of persons on an assisted unit who benefited directly from the assistance rendered by the Coast Guard. (USCG3)
Petroleum	A generic term applied to oil and oil products in all forms, such as crude oil, lease condensate, unfinished oils, petroleum products, natural gas plant liquids, and nonhydrocarbon compounds blended into finished petroleum products. (DOE3) (DOE5) (DOE6)
Petroleum (Oil)	A generic term applied to oil and oil products in all forms, such as crude oil, lease condensate, unfinished oils, petroleum products, natural gas plant liquids, and nonhydrocarbon compounds blended into finished petroleum products.
Petroleum Coke	A residue that is the final product of the condensation process in cracking. This product is reported as marketable coke or catalyst coke. The conversion factor is 5 barrels per short ton. (DOE3) (DOE5)
Petroleum Consumption	A calculated demand for petroleum products obtained by summing domestic production, imports of crude petroleum and natural gas liquids,imports of petroleum products, and the primary stocks at the beginning of the period and then subtracting the exports and the primary stocks at the end of the period. (DOE5) (DOE6)
Petroleum Exports	Shipments of petroleum products from the 50 States and the District of Columbia to foreign countries, Puerto Rico, the Virgin Islands, and other U.S. possessions and territories. (DOE6)
Petroleum Imports	All imports of crude petroleum, natural gas liquids, and petroleum products from foreign countries and receipts from Guam, Puerto Rico, the Virgin Islands, and the Hawaiian Trade Zone. The commodities included are crude oil, unfinished oils, plant condensate, and refined petroleum products. (DOE5) (DOE6)
Petroleum Inventories	The amounts of crude oil, unfinished oil, petroleum products, and natural gas liquids held at refineries, at natural gas processing plants, in pipelines, at bulk terminals operated by refining and pipeline companies, and at independent bulk terminals. Crude oil held in storage on leases is also included. (DOE6)
Petroleum Product	Flammable, toxic, or corrosive products obtained from distilling and processing of crude oil, unfinished oils, natural gas liquids, blend stocks and other miscellaneous hydrocarbon compounds. (49CFR195)
Petroleum Products	Petroleum products are obtained from the processing of crude oil (including lease condensate), natural gas, and other hydrocarbon compounds. Petroleum products include unfinished oils, liquefied petroleum gases, pentanes plus, aviation gasoline, motor gasoline, naphtha-type jet fuel, kerosene-type jet fuel, kerosene, distillate fuel oil, residual fuel oil, petrochemical feedstocks, special naphthas, lubricants, waxes, petroleum coke, asphalt, road oil, still gas, and miscellaneous products. (DOE3) (DOE5)
Petroleum Refinery	An installation that manufactures finished petroleum products from crude oil, unfinished oils, natural gas liquids, other hydrocarbons, and alcohol. (DOE5)
Phase of Operation	The phase of the flight or operation is the particular phase of flight in which the first occurrence or circumstance occurred. In the event that there was more than one occurrence in one operational phase, the same phase is recorded for each of those occurrences. (NTSB1) (NTSB2)
Photo Reconnaissance	Military activity that requires locating individual photo targets and navigating to the targets at a preplanned angle and altitude. The activity normally requires a lateral route width of 16 nautical miles and altitude range of 1,500 feet to 10,000 feet above ground level (AGL). (FAA4)
Pick-Up	Small delivery truck. (ATA1)
Pickup Truck	A motorized vehicle, privately owned and/or operated, with an enclosed cab that usually accommodates 2-3 passengers and an open cargo area in the rear. Pickup trucks usually have about the same wheelbase as a full-size station wagon. (FHWA3)
Pier	See also Dock, Marina, Wharf.
Pig	Trailer transported on flat car. (ATA1)
Piggyback	(See also Intermodal) A transportation concept whereby truck trailers are hauled on railroad flatcars. (ATA1)
Piggyback Trailers	Trailers which are designed for quick loading on railcars. (BOC3)
Pigtail	Cable used to transmit electrical power to trailer. (ATA1)
Pike	Turnpike. (ATA1)
Pike Pole	(See also Sounding Pole) A long pole with a hook on one end used for pulling in a line or wire that is out of reach. It may also be painted with red and white markings to denote a scale of measuring water depth or barge draft. (TNDOT1)
Pilferage	The act of broaching and stealing part or all of the content of cargo. (MARAD1)
Piling	A set of posts forced into the earth to serve as a support, as for a pier, or to resist lateral pressure. (DOI4)
Piling Area	An area identified as a danger to maritime navigation containing one or more structures consisting of piles (long heavy timbers or sections of steel, concrete etc., forced into the earth to serve as a support, as for a pier). (DOI3)
Pilot	The helmsman on a riverboat. Also one who, though not belonging to a ship's company, is licensed to guide a vessel into and out of a port or through dangerous waters. (TNDOT1)
Pilot Briefing	A service provided by a Flight Service Station (FSS) or International Flight Service Station (IFSS) to assist pilots in flight planning. Briefing items may include weather information, Notice to Airmen (NOTAM), military activities, flow control information, and other items as requested. (FAA2) (FAA13) (FAA14)
Pilot Deviation	(See also Operational Deviation, Operational Error, Runway Incursion, Vehicle/Pedestrian Deviation) The actions of a pilot that result in the violation of a Federal Aviation Regulation (FAR) or a North American Aerospace Defense Command (NORAD) Air Defense Identification Zone (ADIZ) tolerance. (FAA3) (FAA10)
Pilot In Command	The pilot responsible for the operation and safety of an aircraft during flight time. (14CFR1)
Pilot Waters	Areas in which the services of a marine pilot are essential. (DOI4)
Pilot Weather Report	A report of meteorological phenomena encountered by aircraft in flight. (FAA4)
Pilotage	Navigation by visual reference to landmarks. (14CFR1)
Pilot's Automatic Telephone Weather Answering Service	A continuous telephone recording containing current and forecast weather information for pilots. (FAA4)
Pilot's Discretion	When used in conjunction with altitude assignments, means that Air Traffic Control (ATC) has offered the pilot the option of starting a climb or descent whenever he wishes and conducting the climb or descent at any rate he wishes. He may temporarily level off at any intermediate altitude. However, once he has vacated an altitude, he may not return to that altitude. (FAA4)
Pinnacle	A tall, slender, spire shaped rock projecting from a level or gently sloping surface. (DOI4)
Pin-Up	Hook tractor to semitrailer. (ATA1)
Pipe	A tube, usually cylindrical, through which a hazardous liquid or carbon dioxide flows from one point to another. (49CFR195)
Pipe Line	Discharge line from a hydraulic dredge. (TNDOT1)
Pipeline	A closed conduit, with pumps, valves and control devices, for conveying fluids, gases, or finely divided solids. (DOI3)
Pipeline Facility	New and existing piping, rights-of-way, and any equipment, facility, or building used in the transportation of gas, hazardous liquids, or carbon dioxide, or in the treatment of gas during the course of transportation. (49CFR193) (49CFR195)
Pipeline Fuel	Gas consumed in the operation of pipelines, primarily in compressors. (DOE3) (DOE5)
Pipelines Except Natural Gas	Includes establishments engaged in the pipeline transportation of petroleum and other commodities, except natural gas. Also included are coal and slurry pipeline operations. (BEA1)
Piping	Pipe, tubing, hoses, fittings, valves, pumps, connections, safety devices or related components for containing the flow of hazardous fluids. (49CFR193)
Piroque	A boat or canoe made from a hollowed tree trunk. (TNDOT1)
Pitch Setting	The propeller blade setting as determined by the blade angle measured in a manner, and at a radius specified by the instruction manual for the propeller. (14CFR1)
Placarded Car	A rail car which is placarded in accordance with the requirements of 49 CFR 172 except those cars displaying only the FUMIGATION placards as required by 49 CFR 172.510. (49CFR171)
Place	An area with definite or indefinite boundaries. (DOI4)
Plain	A region of generally uniform slope, comparatively level, and of considerable extent. (DOI4)
Planning Funds (PL)	Primary source of funding for metropolitan planning designated by the FHWA.
Platform Area	An area identified as a danger to maritime navigation containing one or more platforms (horizontal surfaces raised above the level of the surrounding area for the purpose of supporting equipment used in the drilling). (DOI3)
Platform Body	Truck or trailer body with a floor, but no sides or roof. (ATA1)
Play	Any free movement of components. (49CFR393)
Ply Rating	A measure of the strength of tires based on the strength of a single ply of designated construction. A 12 ply rating does not necessarily mean that 12 plies are present, only that the tire has the strength of 12 standard plies. (TII1) (TII2)
Point Detector	A circuit controller which is part of the switch operating mechanism and operated by a rod connected to a switch, derail or movable point frog to indicate that the point is within a specified distance of the stock rail. (49CFR236)
Point Holding	A specified location, identified by visual or other means, in the vicinity of which the position of an aircraft in flight is maintained in accordance with air traffic control clearances. (FAA4)
Point-Of-Rent	Area on a terminal facility which is assigned for the receipt of inbound cargo from the ship and from which inbound cargo may be delivered to the consignee, and that area which is assigned for the receipt of outbound cargo from shippers for vessel loading. (MARAD1)
Pointway Channel	A cutoff channel which lies across the point of a bend and usually leads deep into another bend. (Conversely, "bendway channel"). (TNDOT1)
Poison Gas In Bulk	The transportation, as cargo, of any poison gas in any quantity. (49CFR387)
Polar Track Structure	A system of organized routes between Iceland and Alaska which overlie Canadian airspace. (FAA4)
Pole Trailer	A motor vehicle without motive power designed to be drawn by another motor vehicle and attached to the towing vehicle by means of a reach or pole, or by being boomed or otherwise secured to the towing vehicle, for transporting long or irregularly shaped loads such as poles, pipes, or structural members capable generally of sustaining themselves as beams between the supporting connections. (49CFR390) (49CFR571)
Pool	(See also Field Area) That area of a river impounded behind a dam. A pool may extend for many miles between one dam and the next. (TNDOT1)
Pool Boat	A towboat with the pilothouse built on the forward end of the cabin rather than on top of the roof. So called because this type is used in areas where low bridges dictate low superstructure. (TNDOT1)
Pool Line	Normal pool water line along the bank. (TNDOT1)
Pool River	A river comprised of various pools or revels formed by dams and having generally a minimum of current, in contrast to open river where currents often become fierce. (TNDOT1)
Pool Site	One or more spent fuel storage pools that has a single cask loading area. Each dry cask storage area is considered a separate site. (DOE5)
Pool Stage	The stage of water that is maintained between two successive dams and is usually the minimum depth that can be maintained and yet have the project depth in the channel. (TNDOT1)
Poor Condition Classification	Major repairs or modifications are required to make the facility operational or to prevent failure. Facility is only partially operational, and is not adequately serving the purpose for which it was constructed. (DOI2)
Pop Rise	A fast rise (usually not a great one) in the river generally caused by a flash flood. (TNDOT1)
Port	1) Harbor with piers or docks ; 2) left side of ship when facing forward ; 3) opening in a ship's side for handling freight. (MARAD2)
Port Authority	An entity of state or local government that owns, operates, or otherwise provides wharf, dock and other marine terminal investments at ports. (MARAD1)
Port Marks	An identifying set of letters, numbers, and/or geometric symbols followed by the name of the port of destination, placed on export shipments. Foreign government requirements may be exceedingly strict in the matter of port marks. (TNDOT1)
Port of Call	Port where a ship discharges or receives traffic. (MARAD2)
Port of Entry	A port at which foreign goods are admitted into the receiving country. (TNDOT1)
Port Tariff	A set of rules and regulations governing a port along with the published fees and charges for using a port's facilities. (TNDOT1)
Portable Tank	A bulk packaging (except a cylinder having a water capacity of 1000 pounds or less) designed primarily to be loaded onto, or on, or temporarily attached to a transport vehicle or ship and equipped with skids, mountings, or accessories to facilitate handling of the tank by mechanical means. It does not include a cargo tank, tank car, multi-unit tank car tank, or trailer carrying 3AX, 3AAX, or 3T cylinders. (49CFR171)
Portage	An overland passage connecting two bodies of water. (TNDOT1)
Position Report	A report over a known location as transmitted by an aircraft to Air Traffic Control (ATC). (FAA4)
Position Symbol	A computer generated indication shown on a radar display to indicate the mode of tracking. (FAA4)
Positive Control	1) Control of all air traffic, within designated airspace, by air traffic control. 2) The separation of all air traffic within designated airspace by air traffic control. (14CFR1) (FAA4)
Possible Injury	Any injury reported or claimed that is not evident. Includes, among others, momentary unconsciousness, claim of injuries not obvious, limping, complaint of pain, nausea, and hysteria.
Possum	(See also Bumpers) Colloquial term for a portable fender or hand fender used to prevent damage to lock walls or vessels when mooring. Should always be used wet. (TNDOT1)
Possum Belly	Livestock trailer with a drop frame to haul small animals (chickens, etc.) underneath heavy cattle. (ATA1)
Post	A long, relatively slender and generally round piece of wood or other material. (DOI4)
Pots	Flares placed on highway to warn traffic of an obstruction or hazard. (ATA1)
Pour On the Coal	Step on the gas. (ATA1)
Power Brake	Open throttle while applying brakes. (ATA1)
Power Train	The group of components used to transmit engine power to the wheels. The power train includes the engine, clutch, transmission universal joints, drive shafts and rear axle gears. (GSA2)
Power Units	The control and pulling vehicle for trailers or semitrailers. (ATA2)
Powered Axle	An axle equipped with a traction device. (49CFR229)
Power-Operated Switch	A switch operated by an electrically, hydraulically, or pneumatically driven switch-and-lock movement. (49CFR236)
Power-Take-Off	A device usually mounted on the side of the transmission or transfer case, or off the front of the crankshaft, and used to transmit engine power to auxiliary equipment such as pumps, winches, etc. (TII1) (TII2)
Prearranged Coordination	A standardized procedure which permits an air traffic controller to enter the airspace assigned to another air traffic controller without verbal coordination. The procedures are defined in a facility directive which ensures standard separation between aircraft. (FAA4)
Precision Approach Procedure	A standard instrument approach procedure in which an electronic glide slope is provided, such as Instrument Landing System (ILS) and Precision Approach Radar (PAR). (14CFR1) (FAA4)
Precision Approach Radar (PAR)	(See also Airport Surveillance Radar, Ground Controlled Approach) Radar equipment in some Air Traffic Control (ATC) facilities operated by the Federal Aviation Administration (FAA) and/or the military services at joint-use civil/military locations and separate military installations to detect and display azimuth, elevation, and range of aircraft on the final approach course to a runway. This equipment may be used to monitor certain nonradar approaches, but is primarily used to conduct a precision instrument approach wherein the controller issues guidance instructions to the pilot based on the aircraft's position in relation to the final approach course (azimuth), the glide path (elevation), and the distance (range) from the touchdown point on the runway as displayed on the radar scope. (FAA4)
Precision Instrument Runway	A runway with an existing or planned precision instrument approach procedure. (FAA12)
Precision Runway Monitor	Provides air traffic controllers with high precision secondary surveillance data for aircraft on final approach to closely spaced parallel runways. High resolution color monitoring displays are required to present surveillance track data to controllers along with detailed maps depicting approaches and no transgression zone. (FAA4)
Preferential Assignment	An agreement whereby one company is given first choice in the use of a particular facility in the port. Also called "first call on berth privilege." (TNDOT1)
Preferential Route	Preferential routes (Preferential departure route (PDR), preferential arrival route (PAR), and preferential departure arrival route (PDAR)) are adapted in Air Route Traffic Control Center (ARTCC) computers to accomplish inter/intrafacility controller coordination and to assure that flight data is posted at the proper control positions. Locations having a need for these specific inbound and outbound routes normally publish such routes in local facility bulletins, and their use by pilots minimizes flight plan route amendments. When the workload or traffic situation permits, controllers normally provide radar vectors or assign requested routes to minimize circuitous routing. (FAA4)
Preferred Highway	See Preferred Route.
Preferred Instrument Flight Rules (IFR) Route	Routes established between busier airports to increase system efficiency and capacity. They normally extend through one or more Air Route Traffic Control Center (ARTCC) areas and are designed to achieve balanced traffic flows among high density terminals
Preferred Route	A highway for shipment of highway route controlled quantities of radioactive materials so designated by a State routing agency, and any Interstate System highway for which an alternative highway has not been designated by such State agency as provided by 49 CFR 177.826(b). (49CFR171)
Premium Gasoline	(See also Gasoline) Gasoline having an antiknock index (R+M/2) greater than 90. Includes both leaded premium gasoline as well as unleaded premium gasoline. (DOE5)
Premium Grade Gasoline	(See also Gasoline) A grade of unleaded gasoline with a high octane rating, (approximately 92) designed to minimize preignition or engine "knocking" by slowing combustion rates. (DOE4) (DOE5)
Premium Leaded Gasoline	(See also Gasoline) Gasoline having an antiknock index (R+M/2) greater than 90 and containing more than 0.05 grams of lead or 0.005 grams of phosphorus per gallon. (DOE5)
Premium Unleaded Gasoline	(See also Fuel, Gasohol, Gasoline, Kerosene) Gasoline having an antiknock index (R+M/2) greater than 90 and containing not more than 0.05 grams of lead or 0.005 grams of phosphorus per gallon. (DOE5)
President’s Budget	A document submitted annually (due by the first Monday in February) by the President to Congress. It sets forth the Administration’s recommendations for the Federal budget for the upcoming fiscal year.
Preventive Maintenance (PM)	(See also Maintenance, Maintenance Control Center) The systematic servicing and inspection of motor vehicles on a predetermined time, mileage or engine-hour basis. The period varies with the type of equipment and the purpose for which it is assigned. (GSA2)
Primary Railway	Tracks providing a direct route through an area. (DOI3)
Primary Transportation	Conveyance of large shipments of petroleum raw materials and refined products usually by pipeline, barge, or ocean-going vessel. All crude oil transportation is primary, including the small amounts moved by truck. All refined product transportation by pipeline, barge, or ocean-going vessel is primary transportation. (DOE5)
Primary Use	The use category in which an aircraft flew the most hours. The ten use categories are aerial application, aerial observation, commuter air carrier, demand air taxi, business transportation, executive/corporate transportation, instructional flying, personal flying, other work, and other. (FAA2) (FAA9)
Principal Arterial	(See also Arterial Highway, Minor Arterial) Major streets or highways, many with multi-lane or freeway design, serving high-volume traffic corridor movements that connect major generators of travel. (NHTSA3)
Principal Impact Point	The impact that is judged to have produced the greatest personal injury or property damage for a particular vehicle. (NHTSA1)
Principal Place of Business	A single location designated by the motor carrier, normally its headquarters, where records required by 49 CFR 387, 390, 391, 395, and 396 will be maintained. Provisions in this subchapter are made for maintaining certain records at locations other than the principal place of business. (49CFR390)
Priority U.S. Mail	Mail bearing postage for air transportation that goes by air on a priority basis at air mail service rates. (BTS5)
Private Carrier	A carrier that provides transportation service to the firm that owns or leases the vehicles and does not charge a fee.
Private Entity	(See also Public Entity) Any entity other than a public entity. (49CFR37)
Private Fleet Vehicle	Ideally, a vehicle could be classified as a member of a fleet if it is 1) Operated in mass by a corporation or institution, 2) Operated under unified control, or 3) Used for non-personal activities. However, the definition of a fleet is not consistent throughout the fleet industry. Some companies make a distinction between cars that were bought in bulk rather than singularly, or whether they are operated in bulk, as well as the minimum number of vehicles that constitute a fleet (i.e. 4 or 10). (DOE6)
Private Label Merchandiser (PLM)	Any person engaged in the business of selling or distributing, under his own trade name, boats or items of associated equipment manufactured by another. (USCG1)
Private Motor Carrier (Of Passengers)	A person who is engaged in an enterprise and provides transportation of passengers, by motor vehicle, that is within the scope of, and in the furtherance of that enterprise. (49CFR390)
Private Motor Carrier (Of Property)	A person who provides transportation of property by motor vehicle, and is not a for-hire motor carrier. (49CFR390)
Private Pilot	A private pilot may not act as a pilot-in-command of aircraft that is carrying passengers for compensation or hire nor act as pilot-in-command in an aircraft that is being operated for compensation or hire (e. g.; one that has been hired to do pipeline patrol but carries no passengers). (FAA2)
Private Road	Private road with restricted public use. (DOI3)
Private Track or Siding	A track located outside of a carrier's right-of-way, yard, or terminals where the carrier does not own the rails, ties, roadbed, or right-of-way and includes track or portion of track which is devoted to the purpose of its user either by lease or written agreement, in which case the lease or written agreement is considered equivalent to ownership. (49CFR171)
Private Transportation	1) Any transport service that is restricted to certain people and is therefore not open to the public at large. 2) Owned or operated by an individual or group, not a governmental entity, for his or its own purposes or benefit. (TRB1)
Privately Owned Airport	An airport which is owned by a private individual or corporation. (FAA2)
Privately Owned Vehicle (POV)	1) A privately-owned vehicle or privately-operated vehicle. 2) Employee's own vehicle used on official business for which the employee is reimbursed by the government on the basis of mileage. (GSA1)
Private-Use Airport	An airport which is not open for the use of the general public. (FAA2)
Pro Forma Invoice	An abbreviated invoice, sent in advance of the regular invoice for the customs clearance of the goods, the purpose being to acquaint the importer and/or government authorities of the importing country with the main details of a shipment to be made and showing reasonably close approximations of the actual weights, quantities, and values. (TNDOT1)
Problem Identification	An element in the planning process which represents the gap between the desired vision, goals and objectives and the current or projected performance of the system
Procedure Turn	The maneuver prescribed when it is necessary to reverse direction to establish an aircraft on the intermediate approach segment or final approach course. The outbound course, direction of turn, distance within which the turn must be completed, and minimum altitude are specified in the procedure. However, unless otherwise restricted, the point at which the turn may be commenced and the type and rate of turn are left to the discretion of the pilot. (FAA4)
Process Fuel	All energy consumed in the acquisition, processing, and transportation of energy. Quantifiable process fuel includes three categories natural gas lease and plant operations, natural gas pipeline operations, and oil refinery operations. (DOE5)
Product	See also Cargo, Commodity, Freight, Goods.
Product Testing	Defect and compliance testing to be carried out under contract from G-NAB. (USCG1)
Production Facility	Piping or equipment used in the production, extraction, recovery, lifting, stabilization, separation or treating of petroleum or carbon dioxide, or associated storage or measurement. To be a production facility under this definition, piping or equipment must be used in the process of extracting petroleum or carbon dioxide from the ground or from facilities where CO2 is produced, and preparing it for transportation by pipeline. This includes piping between treatment plants which extract carbon dioxide, and facilities utilized for the injection of carbon dioxide for recovery operations. (49CFR195)
Productivity	A measure of efficiency of resource utilization; defined as the sum of the outputs divided by the sum of the inputs. (MARAD1)
Profile Descent	An uninterrupted descent (except where level flight is required for speed adjustment; (e.g., 260 knots at 10,000 feet mean sea level) from cruising altitude/level to interception of a glide slope or to a minimum altitude specified for the initial or intermediate approach segment of a nonprecision instrument approach. The profile descent normally terminates at the approach gate or where the glide slope or other appropriate minimum altitude is intercepted. (FAA4)
Program Development	An element in the planning process in which improvements are formalized in the transportation improvement program and provides more detailed strategies.
Programmable Indicator Data Processor (PIDP)	A modification to the AN/TPX-42 interrogator system currently installed in fixed Radar Approach Controls (RAPCON). The Programmable Indicator Data Processor (PIDP) detects, tracks, and predicts secondary radar aircraft targets. These are displayed by means of computer-generated symbols and alphanumeric characters depicting flight identification, aircraft altitude, ground speed, and flight plan data. Although primary radar targets are not tracked, they are displayed coincident with the secondary radar targets as well as with the other symbols and alphanumerics. The system has the capability of interfacing with Air Route Traffic Control Centers (ARTCC). (FAA4)
Programming	Priortizing proposed projects and matching those projects with available funds to accomplish agreed upon, stated needs.
Progressive Taxi	Precise taxi instructions given to a pilot unfamiliar with the airport or issued in stages as the aircraft proceeds along the taxi route. (FAA4)
Prohibited Area	Designated airspace within which the flight of aircraft is prohibited. (FAA8)
Project	A locally sponsored, coordinated, and administered program, or any part thereof, to plan, finance, construct, maintain, or improve an intermodal passenger terminal, which may incorporate civic or cultural activities where feasible in an architecturally or historically distinctive railroad passenger terminal. (49CFR256)
Project Cargo	Large shipments of varied cargo destined for one location and one specific project. (TNDOT1)
Project Depth	The minimum depth of the river channel in a given area prescribed in the channel maintenance and construction program; normally 9 feet throughout the western rivers. Buoys are set in reference to project depth. (TNDOT1)
Promotion and Sales Expenses	Costs incurred in promoting the use of air transportation generally and creating a public preference for the services of particular air carriers. Includes the functions of selling, advertising and publicity, space reservations, and developing tariffs and flight schedules for publication. (BTS4)
Propeller	A device for propelling an aircraft that has blades on an engine-driven shaft and that, when rotated, produces by its action on the air, a thrust approximately perpendicular to its plane of rotation. It includes control components normally supplied by its manufacturer, but does not include main and auxiliary rotors or rotating airfoils of engines. (14CFR1)
Property Damage	Damage to or loss of use of tangible property. (49CFR387)
Property Damage (Transit)	The dollar amount required to repair or replace transit property (including stations, right-of-way, bus stops, and maintenance facilities) damaged during an incident.
Property Damage Accident	An accident for which property damage of $4,400 or more, but no fatalities or injuries, was reported. (FHWA2) (FHWA4)
Property Damage Rate	The average amount of property damage per accident or per one hundred accidents. (FHWA2) (FHWA4)
Property Damage Threshold	The amount of property damage used to determine whether an accident not involving fatalities or injuries is reportable under the Federal Motor Carrier Safety Regulations (FMCSR). In 1994, the property damage threshold was $4,400. (FHWA2) (FHWA4)
Property Loss Prevented	Calculated estimate of the amount of property loss that would have occurred had the Coast Guard not rendered assistance. It is based upon value of property assisted in cases where severity of the incident was evaluated as severe or moderate in nature. (USCG3)
Property-Damage-Only Crash	A police-reported crash involving a motor vehicle in transport on a trafficway in which no injuries of any severity, including fatal injuries, are reported. (NHTSA3) (NHTSA4)
Provisional Rate-Density Relationship	The relationship between fatality rates and average daily traffic. It is based on data for the 4-year period preceding the calendar year for which detailed data are reported. It is labelled "provisional" to make it clear that it is to be used as a guide rather than a standard. A provisional rate-density relationship may be described graphically or mathematically by a rate-density curve. (FHWA1)
Public Aircraft	Aircraft used only in the service of a government, or a political subdivision. It does not include any government-owned aircraft engaged in carrying persons or property for commercial purposes. (14CFR1)
Public Authority	A Federal, State, county, town or township, Indian tribe, municipal or other local government or instrumentality thereof, with authority to finance, build, operate, or maintain highway facilities, either as toll or toll- free highway facilities. (23CFR460)
Public Crossing	A location open to public travel where railroad tracks intersect a roadway that is under the jurisdiction and maintenance of a public authority. (FRA3)
Public Entity	1) Any state or local government; 2) Any department, agency, special purpose district, or other instrumentality of one or more state or local governments; and 3) The National Railroad Passenger Corporation (Amtrak) and any commuter authority. (49CFR37)
Public Hearings	23 U.S.C. 128
Public Inland Waterways Transport (IWT) Enterprise	Inland Waterways Transport (IWT) enterprise which is principally owned (more than 50 per cent of the capital) by the State or public authorities and their enterprises. (TNDOT1)
Public Liability	Liability for bodily injury or property damage and includes liability for environmental restoration. (49CFR387)
Public Meeting or Hearing	A public gathering for the express purpose of informing and soliciting input from interested individuals regarding transportation issues.
Public Participation	The active and meaningful involvement of the public in the development of transportation plans and programs.
Public Road	Any road under the jurisdiction of and maintained by a public authority (federal, state, county, town or township, local government, or instrumentality thereof) and open to public travel.
Public School Transportation	(See also School Bus) Transportation by school bus vehicles of school children, personnel, and equipment to and from a public elementary or secondary school and school-related activities. (49CFR37)
Public Street and Highway Lighting	Includes electricity supplied and services rendered for the purpose of lighting streets, highways, parks, and other public places or for traffic or other signal system service, for municipalities or other divisions or agencies of state or Federal governments. (DOE5)
Public Transit	Passenger transportation services, usually local in scope, that is available to any person who pays a prescribed fare. It operates on established schedules along designated routes or lines with specific stops and is designed to move relatively large numbers of people at one time. (TRB1)
Public Transit Agencies	A public entity responsible for administering and managing transit activities and services. Public transit agencies can directly operate transit service or contract out for all or part of the total transit service provided. (FTA1)
Public Transit System	An organization that provides transportation services owned, operated, or subsidized by any municipality, county, regional authority, state, or other governmental agency, including those operated or managed by a private management firm under contract to the government agency owner. (APTA1)
Public Transportation	Transportation by bus, rail, or other conveyance, either publicly or privately owned, which provides to the public general or special service on a regular and continuing basis. Also known as "mass transportation", "mass transit" and "transit." (APTA1)
Public Use Airport	An airport open to and for public use without prior permission, and without restrictions within the physical capacities of available facilities. May or may not be publicly owned. (FAA2)
Public Use Class I Road	A principal road/rural parkway which constitute the main access route, circulatory tour, or thoroughfare for visitors. (DOI1)
Public Use Class II Road	(See also Overlook Access) A connector road which provides access within an area of scenic, scientific, recreational or cultural interest, such as overlooks, campgrounds, etc. (DOI1)
Public Use Class III Road	A special purpose road which provides circulation within public use areas, such as campgrounds, picnic areas, visitor center complexes, concessioner facilities, etc. These roads generally serve low-speed traffic and are often designed for one way circulation. (DOI1)
Public Use Class IV Road	A primitive road. (DOI1)
Public Use Road	All roads that are intended principally for the use of visitors for access into and within the public use area included. This includes all roads that provide vehicular passage for visitors, or access to such representative park areas as point of scenic or historic interest, campgrounds, picnic areas, lodge areas, etc. County, State, and U.S. numbered highways maintained by the National Park Service are included in this category for purposes of functional classification. (DOI1)
Public Vessel	A vessel owned by and being used in the public service of the United States. It does not include a vessel owned by the United States and engaged in a trade or commercial service or a vessel under contract or charter to the United States. (49CFR171)
Public Way	Any public street, road, boulevard, alley, lane, or highway, including those portions of any public place that have been designated for use by pedestrians, bicycles, and motor vehicles. (TRB1)
Publicly Owned Airport	An airport which is publicly owned and under control of a public agency. (FAA2)
Publico	Passenger vans or Class C motor buses operating with fixed routes but no fixed schedules. Publicos are privately owned and operated mass transit service which is market oriented and unsubsidized, but regulated through a public service commission, State or local government. Publicos are operated under franchise agreements, fares are regulated by route and there are special insurance requirements. Vehicle capacity varies from eight to thirty or more, and the vehicles may be owned or leased by the operator. (FTA1)
Pull Down On	Channel report term used in crossings and meaning that when tow is well over, i.e., two-thirds of the way across, swing the vessel's head down on a new designated mark. (TNDOT1)
Pull Down Shape of Bend	Channel report term meaning to steer into and around the shape of the bend at an easy distance off. (TNDOT1)
Pull Logistics System	"Just in time" logistics system driven by customer demand and enabled by telecommunications and information systems rather than by manufacturing process and inventory stockpiling.
Pull On Down	To change the vessel's course to a point further downstream. (TNDOT1)
Pull the Pin	Release the fifth wheel lock. (ATA1)
Pulpwood Trailer	A trailer that is designed exclusively for harvesting logs or pulpwood and constructed with a skeletal frame with no means for attachment of a solid bed, body, or container, and with an arrangement of air control lines and reservoirs designed to minimize damage in off-road operations. (49CFR393)
Pump Out Facility	A holding place where ships' bilges and cargo are pumped. (DOI4)
Punch	See Drive.
Pup	A short semitrailer used in combination with a dolly and another semitrailer to create a twin trailer. (ATA1)
Purchase or Lease	With respect to vehicles, means the time at which an entity is legally obligated to obtain the vehicles, such as the time of contract execution. (49CFR37)
Purchased Transportation	Transportation service purchased by a public agency from a public or private provider on the basis of a written contract. (TRB1)
Push Logistics System	Inventory based logistics system characterized by regularly scheduled flows of products and high inventory levels.
Pushed Barge Inland Waterways Transport (IWT)	Freight vessel which is designed to be pushed and does not have its own means of mechanical propulsion. (TNDOT1)
Pushed Tanker Barge	Pushed barge for the bulk transport of liquids or gases. (TNDOT1)
Pushed-Towed Barge Inland Waterways Transport (IWT)	Freight vessel which is designed to be either pushed or towed and does not have its own means of mechanical propulsion. (TNDOT1)
Pusher Tug	Powered vessel developing not less than 37 kilowatt (KW) and designed or fitted for the towing of dumb barges, pushed-towed barges, or rafts,and for the pushing of pushed and pushed-towed barges, but not for the carriage of goods. (TNDOT1)
Pusher Vessel	Powered vessel developing not less than 37 KW and designed or fitted for the pushing or pushed or pushed-towed barges but not for the carriage of goods. (TNDOT1)
Push-Towed Tanker Barge	Pushed-towed barge for the bulk transport of liquids or gases. (TNDOT1)
Put On the Air	Apply the brakes. (ATA1)
Put On the Iron	Put on tire chains. (ATA1)
Radar Air Traffic Control Facility (RATCF)	An air traffic control facility, located at a U.S. Naval or Marine Corps Air Station, utilizing surveillance, and normally, precision approach radar and air/ground communication equipment to provide approach control services to aircraft arriving, departing or transiting the airspace controlled by the facility. The facility may be operated by the Federal Aviation Administration (FAA), the United Sates Navy (USN), the United States Marine Corp (USMC), or the FAA & USN and service may be provided for both civil and military airports. (FAA13) (FAA14)
Radar Air Traffic Control Tower	An airport traffic control tower that uses radar and nonradar capabilities to provide approach control services to aircraft arriving, departing, or transiting airspace controlled by the facility. It provides radar air traffic control services to aircraft operating in the vicinity of one or more civil and/or military airports in the terminal area. (FAA13)
Radar Altimeter	Aircraft instrument that makes use of the reflection of radio waves from the ground to determine the height of the aircraft above the surface. (FAA6)
Radar Approach Control (RAPCON)	An air traffic control facility, located at a U.S. Air Force (USAF) base, utilizing surveillance and, normally, precision approach radar and air/ground communication equipment to provide approach control services to aircraft arriving, departing, and transiting the airspace controlled by the facility. The facility may be operated by the Federal Aviation Administration (FAA), or the United States Air Force (USAF). Service may be provided to both civil and military airports. (FAA13) (FAA14)
Radar Approach Control Tower	An airport traffic control tower (ATCT) that uses radar and non-radar capabilities to provide approach control services to aircraft arriving, departing, or transiting airspace controlled by the facility. It provides radar Air Traffic Control (ATC) services to aircraft operating in the vicinity of one or more civil and/or military airports in the terminal area In other words, a radar approach control tower is an ATCT at which airport traffic control specialists are permitted to provide radar approach control service, including extensive vectoring, as well as to handle takeoffs and landings. Radar Acts can be separated into a control tower and a radar room. (FAA10)
Radar Dome	A dome-shaped structure used to protect the antenna of a radar installation. (DOI4)
Radar Reflector	A device capable of or intended for reflecting radar signals. (DOI4)
Radio Contact	The initial radio call-up to a flight service station by en route aircraft, which includes a complete interchange of information and a termination of the contact. (FAA13) (FAA14)
Rag Top	Open top trailer covered with a tarpaulin. (ATA1)
Rags	Bad tires. (ATA1)
Rail	A rolled steel shape laid in two parallel lines to form a track for carrying vehicles with flanged steel wheels. (TRB1)
Rail Car	(See also Railway Car) A car designed to carry freight or non-passenger personnel by rail, and includes a box car, flat car, gondola car, hopper car, tank car, and occupied caboose. (49CFR171)
Rail Joint Bond	A metallic connection attached to adjoining rails to insure electrical conductivity. (49CFR236)
Rail Mode	(See also Rapid Rail, Rapid Transit Rail, Transit Mode, Transit Railroad, Transit Railway) Consists of freight and passenger (including commuter) railroads. (BTS1)
Rail Siding	A very short branch off a main railway line with only one point leading onto it. Sidings are used to allow faster trains to pass slower ones or to conduct maintenance.
Railbus	A relatively light, diesel-powered, two-axle rail vehicle with a body resembling that of a bus. (TRB1)
Rail-Highway Grade Crossing	(See also Grade Crossings; Highway-Rail Crossing) A location where one or more railroad tracks cross a public highway, road, or street or a private roadway, and includes sidewalks and pathways at or associated with the crossing. (49CFR225)
Railroad	A person engaged in transportation by rail. (49CFR171)
Railroad Accident	An event arising from the operation of a railroad which, with minor exceptions results in one or more of the following circumstances 1) Any impact between railroad on-track equipment and an automobile, bus, truck, motorcycle, bicycle, farm vehicle, pedes
Railroad and Railway Electric Service	Electricity supplied to railroads and interurban and street railways, for general railroad use, including the propulsion of cars or locomotives, where such electricity is supplied under separate and distinct rate schedules. (DOE5)
Railroad Car Mile	A single railroad car moved a distance of one mile. (DOE6)
Railroad Crossing Collision	A collision between on-track railroad equipment at a point where tracks intersect. (FRA2)
Railroad Switching and Terminal	A company primarily performing switching service, furnishing terminal trackage, bridges, or other facilities such as union freight stations, operating ferries, or performing any one or combination of these functions. It may coincidentally conduct a regular freight or passenger service. (AAR1)
Railroad Switching and Terminal Establishments	Establishments primarily engaged in the furnishings of terminal facilities for rail passenger or freight traffic for line-haul service, and in the movement of railroad cars between terminal yards, industrial sidings, etc. Terminal companies do not necessarily operate any vehicles themselves, but may operate the stations and terminals. (BOC1)
Railroaded	See Tow.
Railway	A permanent way having one or more rails which provides a track for trains. (DOI4)
Railway Car	(See also Rail Car) A railway car designed to carry freight, railroad personnel, or passengers. This includes boxcars, covered hopper cars, flatcars, refrigerator cars, gondola cars, hopper cars, tanker cars, cabooses, stock cars, ventilation cars, and special cars. It also includes on-track maintenance equipment. (FRA1)
Railway Gauge	Distance between the rails of a track. (DOI3)
Railway Yard	An area provided with a system of tracks and associated structures, where railway trains are assembled, and railway cars are switched, stored or serviced. (DOI3) (DOI4)
Raking Collision	A collision between parts or a consist on an adjacent track, or with a structure such as a bridge. (FRA2)
Ramp	An inclined roadway connecting roads of differing levels. (DOI3)
Ramp Metering	The process of facilitating traffic flow on freeways by regulating the amount of traffic entering the freeway through the use of control devices on entrance ramps. 2) The procedure of equipping a freeway approach ramp with a metering device and traffic signal that allow the vehicles to enter the freeway at a predetermined rate. (TRB1)
Ranking Crew Member	An individual in whom the general charge of the train or yard crew is vested in accordance with the railroad's operating rules. Unless otherwise designated by the railroad, the ranking crew member will be the assigned locomotive engineer. (49CFR218)
Rapid Rail	(See also Rail Mode, Rapid Transit Rail, Transit Mode, Transit Railroad, Transit Railway) A subway-type transit vehicle railway operated on exclusive private rights of way with high level platform stations. Rapid rail also may operate on elevated or at grade level track separated from other traffic. (49CFR37)
Rapid Rail Transit	Transit service using railcars driven by electricity usually drawn from a third rail, configured for passenger traffic, and usually operated on exclusive rights-of-way. It generally uses longer trains and has longer station spacing than light rail.
Rapid Transit	Rail or motorbus transit service operating completely separate from all modes of transportation on an exclusive right-of-way. (APTA1)
Rapid Transit Rail	(See also Rail Mode, Rapid Rail, Transit Mode, Transit Railroad, Transit Railway) Transit service using rail cars driven by electricity usually drawn from a third rail, configured for passenger traffic and usually operated on exclusive rights-of-way. It generally uses longer trains and has longer station spacing than light rail. (FTA1)
Rapids	An area of broken, fast flowing water in a stream, where the slope of the bed increases (but without a prominent break of slope which might result in a waterfall), or where a gently dipping bar of harder rock outcrops. (DOI4)
Ratchet	A heavy turnbuckle with course-screw threads and midships handle, equipped with pelican hooks on both ends for the purpose of rapidly tightening up wire lashings holding the barges of a tow together. It is widely used on the rivers. (TNDOT1)
Rated Maximum Continuous Augmented Thrust	With respect to turbojet engine type certification, means the approved jet thrust that is developed statically or in flight, in standard atmosphere at a specified altitude, with fluid injection or with the burning of fuel in a separate combustion chamber, within the engine operating limitations established under Part 33 of this chapter, and approved for unrestricted periods of use. (14CFR1)
Rated Maximum Continuous Thrust	With respect to turbojet engine type certification, means the approved jet thrust that is developed statically or in flight, in standard atmosphere at a specified altitude, without fluid injection and without the burning of fuel in a separate combustion chamber, within the engine operating limitations established under Part 33 of this chapter, and approved for unrestricted periods of use. (14CFR1)
Rated Takeoff Augmented Thrust	With respect to turbojet engine type certification, means the approved jet thrust that is developed statically under standard sea level conditions, with fluid injection or with the burning of fuel in a separate combustion chamber, within the engine operating limitations established under Part 33 of this chapter, and limited in use to periods of not over 5 minutes for takeoff operation. (14CFR1)
Rated Takeoff Thrust	With respect to turbojet engine type certification, means the approved jet thrust that is developed statically under standard sea level conditions, without fluid injection and without the burning of fuel in a separate combustion chamber within the engine operating limitations established under Part 33 of this chapter, and limited in use to periods of not over 5 minutes for takeoff operation. (14CFR1)
Rate-Regulated Pipelines	The pipelines included in these segments are all Federally or state rate-regulated pipeline operations, which are included in the reporting company's consolidated financial statements. However, at the reporting company's option, intrastate pipeline operations may be included in the U.S. Refining/Marketing Segment if 1) They would comprise less than 5 percent of U.S. Refining/Marketing Segment net property plant & equipment (PP&E), revenues,and earnings in the aggregate; and 2) If the inclusion of such pipelines in the consolidated financial statements adds less than $100 million to the net PP&E reported for the U.S. Refining/Marketing Segment. (DOE5)
Rating	A statement that, as a part of a certificate, sets forth special conditions, privileges, or limitations. (14CFR1)
Ratio Estimate	(See also Estimate Ratio, Mean) The ratio of two population aggregates (totals). For example, "average miles traveled per vehicle" is the ratio of total miles driven by all vehicles, over the total number of vehicles. (DOE4)
Reach	A certain area of a river, usually a straight section. (TNDOT1)
Read the Water	To navigate by visual observation of the water surface; not recommended for newcomers. (TNDOT1)
Rear Axle Capacity	The factor and/or Society of Automotive Engineers (SAE) recommended maximum load that a rear axle assembly is designed to carry as rated at the ground and expressed in pounds. (GSA2)
Rear End Collision	1) A collision in which one vehicle collides with the rear of another vehicle. 2) A collision in which the trains or locomotives involved are traveling in the same direction on the same track. 3) A collision of the front of one vehicle with the rear of another vehicle. Also called rear-end. (FRA2) (NHTSA3)
Rear Extremity	The rearmost point on a vehicle when the vehicle's cargo doors, tailgate or other permanent structure are positioned as they normally are when the vehicle is being driven. Non-structural protrusions such as tail lights, hinges, an latches are deleted from the determination of the rearmost point. (49CFR393)
Rear Overhang	Distance from the center of the rear axle to the end of frame. (TII1) (TII2)
Rearrange Tow	To shift barges in tow. (TNDOT1)
Rebuild	(See also Remanufactured Vehicle) A complete repair of a component with the objective of returning it as nearly as possible to its original and/or performance characteristics. (GSA2)
Rebuilt Caboose	A caboose that has undergone overhaul which has been identified by the railroad as a capital expense under Interstate Commerce Commission accounting standards. (49CFR223)
Rebuilt Locomotive	A locomotive that has undergone overhaul which has been identified by the railroad as a capital expense under Interstate Commerce Commission accounting standards. (49CFR223)
Rebuilt Passenger Car	A passenger car that has undergone overhaul which has been identified by the railroad as a capital expense under Interstate Commerce Commission (ICC) accounting standards. (49CFR223)
Receiver	A device on a locomotive, so placed that it is in position to be influenced inductively or actuated by an automatic train stop, train control or cab signal roadway element. (49CFR236)
Receiver Coil	Concentric layers of insulated wire wound around the core of a receiver of an automatic train stop, train control or cab signal device on a locomotive. (49CFR236)
Receptacle	A containment vessel for receiving and holding materials, including any means of closing. (49CFR171)
Reception Minimum Altitude	The lowest altitude at which an intersection can be determined. (FAA4)
Reconciling Items	Items where accounting practices vary for handling these expenses as a result of local ordinances and conditions. Reconciling items include depreciation and amortization, interest payments, leases and rentals. They are called reconciling items because they are needed to provide an overall total that is consistent with local published reports. (FTA1)
Recreational Boat	1) Any vessel manufactured or used primarily for noncommercial use; leased, rented or chartered to another for the latter's noncommercial use; or 2) Engaged in the carrying of six or fewer passengers. (USCG1)
Recreational Trails Program (RTP)	Provides funds to the States to develop and maintain recreational trails and trail-related facilities for motorized and nonmotorized recreational trail uses. 23 U.S.C. 206.
Reduction	Used to indicate the slower output speed resulting from a ratio proportion (faster on reductions of less than 1; 1) single reduction a single set of reducing gears in the rear axle; 2) double reduction an additional gear-set in the rear axle to reduce output speed further. May or may not be used as a 2-speed rear axle. (TII1) (TII2)
Reef	A ridge of rocks lying near the surface of the sea, which may be visible at low tide, but is usually covered by water. (DOI3) (DOI4)
Reef Area	An area identified as a danger to maritime navigation containing one or more chains of rocks or coral, at or near the surface of the water. (DOI3)
Reef Pool	Pocket of sea/ocean completely surrounded by a coral reef. (DOI3)
Reefer	Refrigerated truck or trailer designed for hauling perishables. (ATA1)
Reefing Current	Current where the swift water reaches the slack water and creates boils or continues boils or turbulent water. It is considered the edge of the reef or what would be a reef were one there. (TNDOT1)
Refined Petroleum Pipelines	Establishments primarily engaged in the pipeline transportation of refined products of petroleum, such as gasoline and fuel oil. (BOC1)
Refined Petroleum Products	Refined petroleum products include but are not limited to gasolines, kerosene, distillates (including No. 2 fuel oil), liquefied petroleum gas, asphalt, lubricating oils, diesel fuels, and residual fuels. (DOE5)
Reflective Material	(See also Left Bank, Reflex Reflector, Retro-Reflective Material, Right Bank) A material conforming to Federal Specification L-S300, "Sheeting and Tape, Reflective; Non-exposed Lens, Adhesive Backing," (September 7, 1965) meeting the performance standard in either Table 1 or Table 1A of Society of Automotive Engineers (SAE) Standard J594f, "Reflex Reflectors" (January, 1977). (49CFR393)
Reflex Reflector	(See also Reflective Material) A device which is used on a vehicle to give an indication to an approaching driver by reflected lighted from the lamps on the approaching vehicle. (49CFR393)
Reformulated Gasoline	1) Gasoline whose composition has been changed to meet performance specifications regarding ozone-forming tendencies and release of toxic substances into the air from both evaporation and tailpipe emissions. Reformulated gasoline includes oxygenates and, compared with gasoline sold in 1990, has a lower content of olefins, aromatics, volatile components, and heavy hydrocarbons. 2) Gasoline specifically developed to reduce undesirable combustion products.
Reformulated Motor Gasoline	(See also Gasoline) Motor gasoline, formulated for use in motor vehicles, the composition and properties of which are certified as reformulated motor gasoline by the Environmental Protection Agency. (DOE3) (DOE5)
Refueling Track	Airspace designated for conducting aerial refueling. (DOI4)
Regional Distribution Port	Waterfront area which 1) Is identifiable with a Standard Metropolitan Statistical Area (SMSA) as defined by the U.S. Bureau of Census, 2) Has 10 or more commercial terminal facilities located within a reasonable distance of the general area, 3) Is served by at least two Class I railroads, and 4) Is served by at least five interstate or U.S. highways. (TNDOT1)
Regional Planning Organization (RPO)	An organization that performs planning for multi-jurisdictional areas. MPOs, regional councils, economic development associations, rural transportation associations are examples of RPOs.
Regional Railroad	Railroad defined as line haul railroad operating at least 350 miles of track and/or earns revenue between $40 million and $266.7 million.
Regionally Significant Project	A project that is on a facility which serves regional transportation needs.
Register Breadth	The breadth of a vessel at its widest part measured from the outerside of the planking or plating on one side to the corresponding point on the opposite side. (USCG4)
Register Depth	The depth of a vessel measured from the underside of the tonnage deck, amidships, to the bottom of the hold. The depth is not the draft of a vessel. (USCG4)
Registered Active General Aviation Aircraft	A civil aircraft registered with the FAA that has been flown one or more hours during the previous calendar year. Excluded are aircraft owned and operated in regularly scheduled, non-scheduled, or charter service by commercial air carriers and aircraft in excess of 12,500 pounds maximum gross takeoff weight, and owned and operated by a commercial operator certificated by the FAA to engage in intrastate common carriage. (FAA14)
Registered Aircraft	Aircraft registered with the Federal Aviation Administration. (FAA6) (FAA9)
Registered Inspector	A person registered with the Department [of Transportation (DOT)] in accordance with 49 CFR 107 Subpart F who has the knowledge and ability to determine if a cargo tank conforms with the applicable DOT specification and has, at a minimum, any of the combinations of education and work experience in cargo tank design, construction, inspection, or repair set out in 49 CFR 171.8. (49CFR171)
Regular Gasoline	See also Gasoline.
Regular Grade Gasoline	(See also Gasoline) A grade of unleaded gasoline with a lower octane rating (approximately 87) than other grades. Octane boosters are added to gasoline to control engine preignition or "knocking" by slowing combustion rates. (DOE4) (DOE5)
Regular Leaded Gasoline	(See also Gasoline) Gasoline having an antiknock index (R+M/2) greater than or equal to 87 and less than or equal to 90 and containing more than 0.05 grams of lead or 0.005 grams of phosphorus per gallon. (DOE5)
Regular Unleaded Gasoline	(See also Gasoline) Gasoline having an antiknock index (R+M/2) greater than or equal to 85 and less than 88, and containing not more than 0.05 grams of lead or 0.005 grams of phosphorus per gallon. (DOE5)
Regularly Employed Driver	A driver who, in any period of 7 consecutive days, is employed or used as a driver solely by a single motor carrier. (49CFR390)
Regulated Motor Carrier	A carrier subject to economic regulation by the Interstate Commerce Commission. (ATA2)
Regulation	Any agency statement of general or particular applicability designed to implement, interpret, or prescribe policy in order to carry out the purpose of a law. Synonymous with "rule" it has the force of law. (USCG1)
Relative Need Formula	An allocation formula used by BIADOT to distribute construction funds to the 12 BIA area offices.
Relayed Cut-Section	A cut-section where the energy for one track circuit is supplied through front contacts or through front and polar contacts of the track relay for the adjoining track circuit. (49CFR236)
Reliability	Refers to the degree of certainty and predictability in travel times on the transportation system. Reliable transportation systems offer some assurance of attaining a given desti­nation within a reasonable range of an expected time. An unreliable transportation system is subject to unexpected delays, increasing costs for system users
Reliever Airport	An airport designated by the Secretary of Transportation as having the function of relieving current or forecast congestion at a commercial service airport and providing more general aviation access to the overall community. (FAA2) (FAA11)
Relocated Threshold	A threshold located at a point on the runway other than the beginning of the runway pavement. The portion of pavement behind a relocated threshold is not available for takeoff. (FAA12)
Remanufactured Vehicle	(See also Rebuild) A vehicle which has been structurally restored and has had new or rebuilt major components installed to extend its service life. (49CFR37)
Remote Areas	Sparsely populated areas such as mountains, swamps, and large bodies of water. (FAA8)
Remote Communications Outlet (RCO)	An unmanned communications facility remotely controlled by air traffic personnel. (FAA8)
Renewable Energy	Energy obtained from sources that are essentially inexhaustible (unlike, for example, the fossil fuels, of which there is a finite supply). Renewable sources of energy include wood, waste, photovoltaic, and solar thermal energy. (DOE3)
Rental of Railroad Cars	Establishments primarily engaged in renting or leasing railroad cars, whether or not also performing services connected with the use thereof, or in performing services connected with the rental of railroad cars. (BOC1)
Replacement Standard	The estimated useful life of a motor vehicle expressed in time (months or years) and/or utilization (miles). (GSA2)
Replacement Vehicle	A vehicle acquired to replace a vehicle in inventory that meets the replacement standard or becomes uneconomical to retain in service. (GSA2)
Reportable Accident	A motor vehicle accident involving a carrier subject to the Department of Transportation Act, which results in a fatality, injury, or property damage of $4,400 or more. (FHWA2) (FHWA4)
Reportable Damage	Includes labor costs and all other costs to repair or replace in kind damaged on-track equipment, signals, track, track structures or roadbed. Reportable damage does not include the cost of clearing a wreck; however, additional damage to the above listed items caused while clearing the wreck is to be included in your damage estimate. Examples of other costs included in reportable damage are 1) Rental and/or operation of machinery such as cranes, bulldozers, etc., including the services of contractors, to replace or repair the track right-of-way and associated structures; and 2) Costs associated with the repair or replacement of roller bearings on units that were derailed or submerged in water (replacement costs means the labor costs resulting from a wheel set change out). (FRA2)
Reportable Death, Injury or Illness	Any event arising from the operation of a railroad which results in 1) death to one or more persons; 2) injury to one or more persons, other than railroad employees, that requires medical treatment; 3) injury to one or more employees that requires medical treatment or results in restriction of work or motion for one or more days, one or more lost workdays, transfer to another job, termination of employment, or loss of consciousness; or 4) any occupational illness of a railroad employee, as diagnosed by a physician. (FRA4)
Reportable Vehicle	All sedans, station wagons, ambulances, buses, carryalls, trucks and truck tractors. Excluded are semitrailers, trailers, and other trailing equipment such as pole trailers, dollies, cable reels, trailer coaches and bodies, portable wheeled compressors, trucks with permanently mounted equipment (e.g. generators, air compressors, etc.), fire trucks, motorcycles, electric and hybrid powered electric vehicles and military design motor vehicles. (GSA1)
Reporting Point	A geographical location in relation to which the position of an aircraft is reported. (14CFR1)
Reporting Threshold	The level of railroad property damage, resulting from a train accident involving on-track equipment, over which a railroad company must report the accident to the Federal Railroad Administration. Reportable damages include the cost of labor and the cost of repairing (or replacing in kind) damaged on-track equipment, track, track structure, or roadbed. (FRA3)
Reporting Unit	Any Coast Guard Command having its own OPFAC (Operating Facility) code (and, therefore, an individual accountability). (USCG3)
Representative Vehicle	A motor vehicle which represents the type of motor vehicle that a driver applicant operates or expects to operate. (49CFR383)
Rescue Coordination Center (RCC)	A search and rescue (SAR) facility equipped and manned to coordinate and control SAR operations in an area designated by the SAR plan. The U.S. Coast Guard and the U.S. Air Force have responsibility for the operation of RCCs. (FAA8)
Research	Investigation or experimentation aimed at the discovery of new theories or laws and the discovery and interpretation of facts or revision of accepted theories or laws in the light of new facts. (49CFR171)
Research and Special Programs Administration (RSPA)	The Administration was established formally on September 23, 1977. It is responsible for hazardous materials transportation and pipeline safety, transportation emergency preparedness, safety training, multimodal transportation research and development activities, and collection and dissemination of air carrier economic data. It includes the Office of Hazardous Materials Safety; the Office of Pipeline Safety; the Office of Research Technology, and Analysis; the Office of University Research and Education; the Office of Automated Tariffs; the Office of Research Policy and Technology Transfer; the Volpe National Transportation Systems Center; and the Transportation Safety Institute. (OFR1)
Reset Device	A device whereby the brakes may be released after an automatic train control brake application. (49CFR236)
Residential District	The territory adjacent to and including a highway which is not a business district and for a distance of 300 feet or more along the highway is primarily improved with residences. (49CFR390)
Residential Transportation Energy Consumption Survey (RTECS)	This survey was designed by the Energy Information Administration of the Department of Energy to provide information on how energy is used by households for personal vehicles. It has been conducted five times since 1979, the most recent being 1991. (DOE6)
Residential Vehicle	Motorized vehicles used by U.S. households for personal transportation. Excluded are motorcycles, mopeds, large trucks, and buses. Included are automobiles, station wagons, passenger vans, cargo vans, motor homes, pickup trucks, and jeeps or similar vehicles. In order to be included, vehicles must be 1) Owned by members of the household, or 2) Company cars not owned by household members but regularly available to household members for their personal use and ordinarily kept at home, or 3) Rented or leased for 1 month or more. (DOE5)
Residual Fuel Oil	The heavier oils that remain after the distillate fuel oils and lighter hydrocarbons are distilled away in refinery operations and that conform to American Society for Testing and Materials Specifications D396 and 976. Includes, among others, Navy Special oil used in steam-powered vessels in government service and No. 6 oil used to power ships. Imports of residual fuel oil include imported crude oil burned as fuel.
Residual Fuel Oils	The heavier oils that remain after the distillate fuel oils and lighter hydrocarbons are distilled away in refinery operations and that conform to American Society for Testing and Materials (ASTM) Specifications D396 and 975. Included are No. 5, a residual fuel oil of medium viscosity; Navy Special, for use in steam-powered vessels in government service and in shore power plants; and No. 6, which includes Bunker C fuel oil and is used for commercial and industrial heating, electricity generation, and to power ships. Imports of residual fuel oil include imported crude oil burned as fuel. (DOE3) (DOE5)
Residue	The hazardous material remaining in a packaging, including a tank car, after its contents have been unloaded to the maximum extent practicable and before the packaging is either refilled or cleaned of hazardous material and purged to remove any hazardous vapors. (49CFR171)
Resource	Any personnel or property used in rendering assistance. (USCG3)
Response Activities	The containment and removal of oil from the water and shorelines, the temporary storage and disposal of recovered oil, or the taking of other actions as necessary to minimize or mitigate damage to the environment. (49CFR194)
Response Area	The inland zone or coastal zone, as defined in the National Contingency Plan (40 CFR 300), in which the response activity is occurring. (49CFR194)
Response Plan	The operator's core plan and the response zone appendices for responding, to the maximum extent practicable, to a worse case discharge of oil,or the substantial threat of such a discharge. (49CFR194)
Response Resources	The personnel, equipment, supplies, and other resources necessary to conduct response activities. (49CFR194)
Response Zone	A geographic area either along a length of pipeline or including multiple pipelines, containing one or more adjacent line sections, for which the operator must plan for the deployment of, and provide, spill response capabilities. The size of the zone is determined by the operator after considering available capability, resources, and geographic characteristics. (49CFR194)
Rest Site	A roadside area usually having facilities for people and/or vehicles. (DOI3)
Restoring Feature	An arrangement on an electro-pneumatic switch by means of which power is applied to restore the switch movement to full normal or to full reverse position, before the driving bar creeps sufficiently to unlock the switch with control level in normal or reverse position. (49CFR236)
Restraint Usage	(See also Mandatory Use Seat Belt Law, Manual Restraint System) Manually operated restraint systems include shoulder belts, lap belts, lap and shoulder belt combinations, or child safety seats. Automatic restraint systems include passive belts and air bag systems. (NHTSA2)
Restricted Area	Airspace designated under Federal Aviation Regulations (FAR), Part 73, within which the flight of aircraft, while not wholly prohibited, is subject to restriction. Most restricted areas are designated joint use and Intermediate Fix/Visual Flight Rules IF/VFR operations in the area may be authorized by the controlling Air Traffic Control (ATC) facility when it is not being utilized by the using agency. Restricted areas are depicted on en route charts. Where joint use is authorized, the name of the ATC controlling facility is also shown. (FAA8)
Restricted Road	Public road with restricted public use. (DOI3)
Restricted Speed	A speed that will permit stopping within one-half the range of vision, but not exceeding 20 miles per hour. (49CFR236)
Restriction of Work or Motion	The inability of a railroad employee to perform all normally assigned duties because of injury or occupational illness, and includes the assignment of a railroad employee to another job or to less than full time work at a temporary or permanent job. (49CFR225)
Retail Gasoline (Motor) Prices	(See also Gasoline) Motor gasoline prices calculated each month by the Bureau of Labor Statistics (BLS) in conjunction with the construction of the Consumer Price Index (CPI). Those prices are collected in 85 urban areas selected to represent all urban consumers about 80 percent of the total U.S. population. The service stations are selected initially, and on a replacement basis, in such a way that they represent the purchasing habits of the CPI population. Service stations in the current sample include those providing all types of service (i.e., full -, mini -, and self-service). (DOE5)
Retained Earnings	Net income or loss from all operations of the corporate entity less dividends and net unrealized loss on noncurrent marketable equity securities. (BTS4)
Retarding Basin	Basin or embarked area for retarding the flow of flood waters. (DOI3)
Retro-Reflective Material	(See also Reflective Material) A type of material applied either in strips or sheets which reflects searchlight illumination; used on all aids to navigation, both unlighted and lighted, afloat and ashore. (TNDOT1)
Revenue	Remuneration received by carriers for transportation activities.
Revenue Aligned Budget Authority (RABA)	The adjustment in funding made annually to the highway program, beginning in FY 2000, as a result of the adjustment in the firewall level for highways. The firewall level is adjusted to reflect revised receipt estimates for the Highway Account of the Highway Trust Fund. Then, adjustments equal to the firewall adjustment—are made to Federal-Aid highway authorizations and obligation limitation for the fiscal year.
Revenue Bonds	The most common form of financing for port authorities. The bonds usually name a specific facility whose income is pledged as security. The power to issue revenue bonds, as well as any other fiscal power, must come from the authority's charter or legislative acts authorizing the creation of such an authority. (TNDOT1)
Revenue Load Factor	The percent that revenue ton-miles (passenger and nonpassenger) are of available ton-miles in revenue services, representing the proportion of the overall capacity that is actually sold and utilized. (BTS6)
Revenue Load Per Aircraft Mile	The average total tonnage carried per aircraft in revenue services derived by dividing overall revenue ton miles by the aircraft miles flown in revenue services. (BTS5)
Revenue Passenger	1) Air Person receiving air transportation from an air carrier for which remuneration is received by the carrier. Air carrier employees or others, except ministers of religion, elderly individuals, and handicapped individuals, receiving reduced rate charges (less than the applicable tariff) are considered nonrevenue passengers. Infants, for whom a token fare is charged, are not counted as passengers. 2) Transit Single-vehicle transit rides by initial-board (first-ride) transit passengers only. Excludes all transfer rides and all nonrevenue rides. 3) Rail Number of one-way trips made by persons holding tickets.
Revenue Passenger Enplanements	(See also Enplanement) 1) The total number of passengers boarding aircraft. Includes both originating and connecting passengers. 2) Total number of revenue passengers boarding aircraft in scheduled service including origination, stopover or connecting passengers. (ATAB1) (BTS5) (FAA14)
Revenue Passenger Enplanements (Air)	The total number of passengers boarding aircraft. Includes both originating and connecting passengers.
Revenue Passenger Load Factor	The percent that revenue passenger-miles are of available seat-miles in revenue passenger services, representing the proportion of aircraft seating capacity that is actually sold and utilized. (BTS5) (FAA14)
Revenue Passenger Load Factor (Air)	Revenue passenger-miles as a percentage of available seat-miles in revenue passenger services. The term is used to represent the proportion of aircraft seating capacity that is actually sold and utilized.
Revenue Passenger Mile (RPM)	One revenue passenger transported one mile in revenue service. Revenue passenger miles are computed by summation of the products of the revenue aircraft miles flown on each inter-airport hop multiplied by the number of revenue passengers carried on that hop. (BTS5) (BTS6) (FAA14)
Revenue Passenger Ton-Mile (Air)	One ton of revenue passenger weight (including all baggage) transported one mile. The passenger weight standard for both domestic and international operations is 200 pounds.
Revenue Passenger Trips	The number of fare-paying transit passengers with each person counted once per trip; excludes transfer and non-revenue trips. (APTA1)
Revenue Passenger-Mile	One revenue passenger transported one mile.
Revenue Plane-Miles	The total plane miles flown in revenue service. (NTSB1)
Revenue Seat Mile	The movement of one transit passenger seat over 1 mile. In other words, the total number of revenue seat miles for a vehicle is obtained by multiplying the number of revenue seats in the vehicle by the number of revenue miles traveled. (TRB1)
Revenue Service	The time when a vehicle is available to the general public and there is a reasonable expectation of carrying passengers that either directly pay fares, are subsidized by public policy, or provide payment through some contractual arrangement. Vehicles operated in fare free service are considered in revenue service. Revenue service excludes deadhead, school bus, and charter service. (FTA1)
Revenue Ton Mile	The movement of a ton of freight one mile for revenue. (AAR1)
Revenue Ton Mile (RTM)	One ton of revenue traffic transported one mile. (ATAB1) (BTS5) (BTS6) (FAA14)
Revenue Ton-Mile	One short ton of freight transported one mile.
Revenue Ton-Miles	Revenue freight traffic measured in ton-miles. (FRA3)
Revenue Vehicle Mile	The distance in miles that a revenue vehicle is operated while it is available for passenger service. (TRB1)
Revenue Vehicle Operation	All activities associated with revenue vehicle operation including moving revenue vehicles along routes while boarding and discharging passengers, deadheading, laying-over, moving operators to relief points, and assisting passenger loading. (FTA1)
Revenue Vehicle-Miles (Transit)	One vehicle (bus, trolley bus, or streetcar) traveling one mile, while revenue passengers are on board, generates one revenue vehicle-mile. Revenue vehicle-miles reported represent the total mileage traveled by vehicles in scheduled or unscheduled revenue-producing services.
Revenue Vehicles	The floating and rolling stock used in providing transit service for passengers. The term revenue vehicles includes the body and chassis and all fixtures and appliances inside or attached to the body or chassis, except fare collection equipment and revenue vehicle movement control equipment (radios). (FTA1)
Reverse Commuting	Movement in a direction opposite the main flow of traffic, such as from the central city to a suburb during the morning peak period. (APTA1)
Ride Quality	A measure of the comfort level experienced by a passenger in a moving vehicle, including the vibration intensity and frequency, accelerations (longitudinal, transverse, and vertical), jerk, pitch, yaw, and roll. (TRB1)
Ride Shot Gun	Not driving; riding on right side of cab. (ATA1)
Ridership	The number of rides taken by people using a public transportation system in a given time period. (APTA1)
Ridesharing	A form of transportation, other than public transit, in which more than one person shares the use of the vehicle, such as a van or car, to make a trip. Also known as "carpooling" or "vanpooling." (APTA1)
Ridge Line	The line separating drainage basins. (DOI4)
Rig	Truck, tractor-semitrailer, truck and full trailer, or other combination. (ATA1)
Rigging	A collective term describing wire cables, chain length, ratchet turnbuckles, and other miscellaneous associated gear used for securing barges in a tow. (TNDOT1)
Right Bank	(See also Left Bank, Reflective Material) The right descending bank of a river on which side are maintained black buoys, green or white lights, and white or silver reflective material. (TNDOT1)
Right of Way	The land (usually a strip) acquired for or devoted to highway transportation purposes. (FHWA2)
Right-Hand Draft	Current which pulls tow to right. (TNDOT1)
Riparian	Pertaining to land adjacent to the water line. (TNDOT1)
Riprap	A group of concrete slabs or stones used in bank improvement and around other types of marine construction to protect against erosion from the swift water. (TNDOT1)
Rising River	The river condition when gage readings are increasing day by day. (TNDOT1)
River Gage	A gage measuring height of water located farther along the river than just above and below a dam. (TNDOT1)
River Mileage	Designated mileage from the mouth of the river used for identifying locations along the riverbanks. An exception is the Ohio River, on which mileage commences from the head of the river in lieu of the mouth. (TNDOT1)
River Stage	The height of the water at a certain location on a given day. (TNDOT1)
River Wall	The lock wall on the river side. (TNDOT1)
Road	An open way for the passage of vehicles, persons, or animals on land. (DOI4)
Road Call	(See also Roadcalls for Mechanical Failure, Roadcalls for Other Reasons) Unscheduled maintenance requiring either the emergency repair or service of a piece of equipment in the field or the towing of the unit to the garage or shop. (GSA2)
Road Class	The category of roads based on design, weatherability, their governmental designation, and the Department of Transportation functional classification system. (DOI3)
Road Functional Classification	The classification of a road in accordance with the Bureau of Land Management (BLM) 9113.16. Code as follows C-collector, L-local, R-resource. (DOI2)
Road Gate	Gate blocking entrance to a road. (DOI3)
Road Hog	Motorist who takes more than his share of the highway. (ATA1)
Road Miles	The length in miles of the single or first main track measured by the distance between terminals or stations, or both. Road miles does not include industrial and yard tracks, sidings, and all other tracks not regularly used by road trains operated in such specific service, and lines operated under a trackage rights agreement. (49CFR245)
Road Oil	Any heavy petroleum oil, including residual asphaltic oil, that is used as a dust palliative and surface treatment on roads and highways. It is generally produced in six grades from zero, the most liquid, to five, the most viscous.
Road or Trail Restrictions	Limitations placed on the use of a road or trail. Code as follows S-seasonal closure, Y-closed yearlong to motorized vehicles, R-restriction on types of traffic allowed on road, L-limitations on vehicle dimensions, weight, or speed, N-no restrictions applied, B-no bicycles, E-no equestrians, M-no motorized vehicle, P-permit required for use. (DOI2)
Roadbed	1) In railroad construction, the foundation on which the ballast and track rest. 2) In highway construction, the graded portion of a highway within top and side slopes, prepared as a foundation for the pavement structure and shoulder. (TRB1)
Roadcalls For Mechanical Failure	(See also Road Call) A revenue service interruption caused by failure of some mechanical element of the revenue vehicle. Mechanical failures include breakdowns of air equipment, brakes, body parts, doors, cooling system, heating system, electrical units, fuel system, engine, steering and front axle, rear axle and suspension, and torque converters. (FTA1)
Roadcalls For Other Reasons	(See also Road Call) A revenue service interruption caused by tire failure, farebox failure, wheel chair lift failure, air conditioning system, out of fuel-coolant-lubricant, and other causes not included as mechanical failures. (FTA1)
Roadway	See also Road.
Roadway Element	That portion of the roadway apparatus of automatic train stop, train control, or cab signal system, such as electric circuit, inductor, or trip arm to which the locomotive apparatus of such system is directly responsive. (49CFR236)
Roadway Function Class	The classification describing the character of service the street or highway is intended to provide. (NHTSA3)
Rock Area	An area identified as a danger to maritime navigation containing one or more rocks. (DOI3)
Rock Berm	A mound or strip of stone placed against the side of a structure near the base to act as a buttress. (TNDOT1)
Rock Cut	A dredged channel cut through rocky bottom. Requires particularly careful marking with aids to navigation and is generally narrow, requiring extreme caution on the part of the navigator. (TNDOT1)
Rock It	To free vehicle from mud or snow by alternately driving forward and reverse. (ATA1)
Rocker Link	That portion of an interlocking machine which transmits motion between the latch and the universal link. (49CFR236)
Rocket	An aircraft propelled by ejected expanding gases generated in the engine from self-contained propellants and not dependent on the intake of outside substances. It includes any part which becomes separated during the operation. (14CFR1)
Rocky Mountain Double	A combination vehicle consisting of a tractor, a 45 to 48 foot semitrailer and a shorted 28 foot semitrailer. (ATA2)
Roll and Rest	When a long haul driver drives and stops at regular intervals to sleep. (ATA1)
Roll On/Roll Off	A method of ocean cargo service using a vessel with ramps which allows wheeled vehicles to be loaded and discharged without cranes. (MARAD2)
Roll On/Roll Off (RO/RO) Vessel	Ships which are especially designed to carry wheeled containers trailers, or other wheeled cargo, and use the roll-on/roll-off method for loading and unloading. (MARAD1)
Roll on/Roll off Cargo (RO/RO)	Wheeled cargo, such as automobiles, or cargo carried on chassis that can be rolled on or off vehicles without using cargo handling equipment.
Roll On/Roll Off Vessel (Water)	Ships that are designed to carry wheeled containers or other wheeled cargo and use the roll on/roll off method for loading and unloading.
Roll Vessel	A vessel designed to permit rail cars or highway trailers to move from the terminal to the vessel over a ramp, with a switch engine as motor power to move the containers. (TNDOT1)
Roller Dam	A dam constructed of a series of concrete piers across the river with a series of steel cylindrical drums between each pier. These drums are rolled up and down an inclined gear track in the piers, thus controlling the flow of water through the dam. Water passes under the rollers rather than over the top as in a fixed or wicket dam. (TNDOT1)
Roller Gate	A gate designed to control the flow of water through a roller dam. (TNDOT1)
Rolling Equipment	Includes locomotives, railroad cars, and one or more locomotives coupled to one or more cars. (49CFR218)
Rolling Stock	The vehicles used in a transit system, including buses and rail cars. (APTA1)
Rollover	(See also Accident, Jackknife) Rollover is defined as any vehicle rotation of 90 degrees or more about any true longitudinal or lateral axis. (NHTSA1) (NHTSA3)
Rolltop	Trailer with a sliding roof to permit crane loading. (ATA1)
Root of a Dike	The portion of the dike that abuts the adjacent shore. (TNDOT1)
Rotating Airport Beacon	A visual Navigation Aid (NAVAID) operated at many airports. At civil airports, alternating white and green flashes indicate the location of the airport. At military airports, the beacons flash alternately white and green, but are differentiated from civil beacons by dual peaked (two quick) white flashes between the green flashes. (FAA4)
Rotation	The reassignment of vehicles either within or between agencies to equalize mileage. (GSA2)
Rotorcraft	A heavier-than-air aircraft that depends principally for its support in flight on the lift generated by one or more rotors. (14CFR1) (AIA1) (FAA3)
Rotorcraft Load Combination	The combination of a rotorcraft and an external load, including the external load attaching means. (14CFR1)
Rotorcraft Load Combination Class A	A rotorcraft load combination means one in which the external load cannot move freely, cannot be jettisoned, and does not extend below the landing gear. (14CFR1)
Rotorcraft Load Combination Class B	A rotorcraft load combination means one in which the external load is jettisonable and is lifted free of land or water during the rotorcraft operation. (14CFR1)
Rotorcraft Load Combination Class C	A rotorcraft load combination means one in which the external load is jettisonable and remains in contact with land or water during the rotorcraft operation. (14CFR1)
Rotorcraft Load Combination Class D	A rotorcraft load combination means one in which the external load is other than a Class A, B, or C and has been specifically approved by the [Federal Aviation Administration (FAA)] Administrator for that operation. (14CFR1)
Roundabout	Area of water subject to a routing measure restricting ship movement to a counterclockwise direction. (DOI4)
Route	A defined path, consisting of one or more courses in a horizontal plane, which aircraft traverse over the surface of the earth. (FAA8)
Route Locking	Electric locking, effective when a train passes a signal displaying an aspect for it to proceed, which prevents the movement of any switch, movable-point frog, or derail in advance of the train within the route entered. It may be so arranged that as a train clears a track section of the route, the locking affecting that section is released. (49CFR236)
Route Miles	The total number of miles included in a fixed route transit system network. (APTA1)
Route Segment	A part of a route. Each end of that part is identified by a continental or insular geographical location; or a point at which a definite radio fix can be established. (14CFR1)
Rubbing Stake (or Timber)	A timber, or timbers, usually parallel to the water surface, used as fenders along which boats or barges may slide, or rub, without damage to the craft or permanent structure. (TNDOT1)
Rulemaking (Regulations)	The authority delegated to administrative agencies by Congress or State legislative bodies to make rules that have the force of law. Frequently, statutory laws that express broad terms of a policy are implemented more specifically by administrative rules, regulations, and practices. (DOE5)
Rules of the Road	Statutory and regulatory rules governing navigation of vessels. (USCG2)
Run Off	(See also Runoff) That portion of the precipitation that flows over the land surface and ultimately reaches streams to complete the water cycle. Melting snow is an important source of this water as well as all amounts of surface water that move to streams or rivers through any given area of a drainage basin. (DOE5)
Runaway Truck Ramp	A short inclined roadway constructed of sand or other unconsolidated material that exits gradually from and generally runs adjacent to the right lane of a descending highway, expressly for the purpose of stopping runaway trucks. (DOI3)
Running Clearance	The distance from the surface on which an automobile is standing to the lowest point on the automobile, excluding unsprung weight. (49CFR523)
Running Track	A track providing end-to-end line continuity and used for working regular trains between stations or places indicated in tariffs as independent points of departure or arrival for the conveyance of passengers or goods. (UN1)
Runoff	(See also Run Off) The water from all tributaries that enters into a river. (TNDOT1)
Runway	A defined rectangular area on an airport prepared for the landing or takeoff of airplanes. (FAA12)
Runway Blast Pad	A surface adjacent to the ends of runways provided to reduce the erosive effect of jet blast and propeller wash. (FAA12)
Runway Incursion	(See also Operational Deviation, Operational Error, Pilot Deviation, Vehicle/Pedestrian Deviation) Any occurrence at an airport involving an aircraft, vehicle, person, or object on the ground that creates a collision hazard or results in loss of separation with an aircraft taking off intending to take off; landing or intending to land. Note Runway incursions result from one of the following four types of airport surface occurrences pilot deviations, operational errors, vehicle operator/pedestrian deviations, and pilot/vehicle operator/pedestrian judgmental errors.) (FAA3) (FAA10)
Runway Obstacle Free Zone (OFZ)	(See also Inner-Approach Obstacle Free Zone, Inner-Transitional Obstacle Free Zone, Obstacle Free Zone) The runway Obstacle Free Zone (OFZ) is a defined volume of airspace centered above the runway. The runway OFZ is the airspace above a surface whose elevation at any point is the same as the elevation of the nearest point on the runway centerline. The runway OFZ extends 200 feet beyond each end of the runway. The width is as follows 1) For runways serving large airplanes, the greater of a) 400 feet, or b) 180 feet, plus the wingspan of the most demanding airplane plus 20 feet per 1,000 feet of airport elevation. 2) For runways serving only small airplanes a) 300 feet for precision instrument runways. b) 260 feet for other runways serving small airplanes with approach speeds of 50 knots or more. c) 120 feet for other runways serving small airplanes with approach speeds of less than 50 knots. (FAA4)
Runway Protection Zone (RPZ)	An area off the runway end (formerly the clear zone) used to enhance the protection of people and property on the ground. (FAA12)
Runway Safety Area (RSA)	A defined surface surrounding the runway prepared or suitable for reducing the risk of damage to airplanes in the event of an undershoot, overshoot, or excursion from the runway. (FAA12)
Runway Transgression	Any erroneous occupation of a runway at a controlled airport by an aircraft or other controlled vehicle. (FAA10)
Runway Type	A runway use classification related to its associated aircraft approach procedure. (FAA12)
Rural	Usually refers to areas with population less than 5,000. (DOE6)
Rural Area	Include all areas of a state outside of the Federal Highway Administration (FHWA) approved adjusted census boundaries of small urban and urbanized areas. (FHWA2)
Rural Arterial Routes	Those public roads that are functionally classified as a part of the rural principal arterial system or the rural minor arterial system as described in volume 20, appendix 12, Highway Planning Program Manual. (23CFR470)
Rural Highway	Any highway, road, or street that is not an urban highway.
Rural Major Collector Routes	Those public roads that are functionally classified as a part of the major collector subclassification of the rural collector system as described in volume 20, appendix 12, Highway Planning Program Manual. (23CFR470)
Rural Mileage (Highway)	Roads outside city, municipal district, or urban boundaries.
Saddle Tank	Fuel storage area on a tractor. (ATA1)
Saddle-Mount	(See also King-Pin Saddle-Mount, Lower-Half of Saddle Mount, Upper-Half of Saddle Mount) A device, designed and constructed as to be readily demountable, used in driveaway-towaway operations to perform the functions of a conventional fifth wheel. (49CFR393)
Safety Alert	A safety alert issued by Air Traffic Control (ATC) to aircraft under their control. (FAA8)
Safety Defect	A defect in a product subject to the provisions of the 46 U.S.C. Chapter 43, which creates a substantial risk of personal injury to the public. The defective part or area may be under the provisions of 46 (U.S.C.) Chapter 43, and if so regulated, may or may not be in compliance with that standard. (USCG1)
Safety Harbor	An area which has been cleared of tree stumps before impoundment of the pool and in which a safe project depth is guaranteed for the mooring of vessels. First-class safety harbors are marked with orange boards. A second-class harbor has project depth only at pool stage, whereas the first class harbor maintains project depth even at drawn down winter levels of the pool. (Term peculiar to the Tennessee River.) (TNDOT1)
Safety Harbor Landing Markers	White arrow shaped boards pointing in the direction of cleared areas safe for mooring in demand reservoirs (used only on the Tennessee River). They indicate that the site has been cleared of tree stumps to a specified depth. (TNDOT1)
Safety Landing	Similar to safety harbor except that it consists of a small cleared area along the bank. (Found only on the Tennessee River at present). (TNDOT1)
Safety Management System	A systematic process that has the goal of reducing the number and severity of transportation related accidents by ensuring that all opportunities to improve safety are identified, considered and implemented as appropriate.
Sailboat	Craft intended to be propelled primarily by sail, regardless of size or type. (USCG2)
Sailing Line	A printed course line appearing on river charts showing the recommended general course at the time the chart was issued. Usually out of date for open rivers; the navigator should consult the latest channel reports. (TNDOT1)
Saint Lawrence Seaway Development Corporation (SLSDC)	The Saint Lawrence Seaway Development Corporation was established by act of May 13, 1954 (33 U.S.C. 981-990), as an operating administration of the Department of Transportation. The Corporation, a wholly Government owned enterprise, is responsible for the development, operation, and maintenance of that part of the St. Lawrence Seaway between the port of Montreal and Lake Erie, within the territorial limits of the United States. The function of the Seaway Corporation is to provide a safe, efficient, and effective water artery for maritime commerce, both in peacetime and in time of national emergency. (OFR1)
Sales-Weighted Miles Per Gallon	Calculation of a composite vehicle fuel economy based on the distribution of vehicle sales. (DOE6)
Sampling	A statistical technique for the collection of passenger mile data. The sampling technique may be one of the FTA approved procedures or an alternative methodology which meets FTA's requirements for the statistical reliability (95% confidence and 10% precision). (FTA1)
Sand Digger	A dredge engaged in obtaining sand and gravel from the riverbed. (TNDOT1)
SAR Facility	(See also Search and Rescue) A regular Reserve operated or augmented, or Auxiliary operated Coast Guard unit, such as an air station, small boat station, base (or support center), group/section, or other shore unit which has search and rescue as a primary mission. (USCG3)
Satellite	A body that revolves around a larger body, such as the moon revolving around the earth, or a man-made object revolving about any body such as the sun, earth or moon. (AIA1)
Scheduled Air Transportation	Establishments primarily engaged in furnishing air transportation over regular routes and on regular schedules. This industry includes Alaskan carriers operating over regular or irregular routes. (BOC1)
Scheduled Aircraft Miles Completed	The aircraft miles completed on scheduled flights, computed between only those scheduled points actually served. (BTS5)
Scheduled Airlines, U.S.	Carriers certificated by the Federal government under Section 401 of the Federal Aviation Act permitting the operation of large aircraft larger than 60 seats. (ATAB1)
Scheduled Revenue Service	The total service scheduled to be provided for picking up and discharging passengers. Scheduled revenue service is computed from internal transit agency planning documents (e.g., run paddles, trip tickets and public timetables), and includes the whole trip (e.g., deadhead, layover/recovery, and actual picking up and discharging of passengers). Schedule service excludes service interruptions and special additional services. (FTA1)
Scheduled Service	Transport service operated over routes pursuant to published flight schedules which are openly advertised with dates or times (or both) or otherwise made readily available to the general public or pursuant to mail contracts with U.S. Postal services. (FAA11)
Scheduled Service (Air)	Transport service operated on published flight schedules.
School and Other Nonrevenue Bus	(See also Intercity Bus, Motor Bus, Motorbus, Transit Bus) Bus services for which passengers are not directly charged for transportation, either on a per passenger or per vehicle basis. (DOE6)
School Bus	A passenger motor vehicle that is designed or used to carry more than 10 passengers, in addition to the driver, and, as determined by the Secretary of Transportation, is likely to be significantly used for the purpose of transporting pre-primary, primary, or secondary school students between home and school.
School Bus Hours	The vehicle hours of travel by a revenue vehicle while serving as a school bus. School bus hours are only hours where a bus is primarily or soley dedicated to carrying school passengers. (FTA1)
School Bus Operation	The use of a school bus to transport only school children and/or school personnel from home to school and from school to home. (49CFR390)
School Bus Related Crash	Any crash in which a vehicle, regardless of body design, used as a school bus is directly or indirectly involved, such as a crash involving school children alighting from a vehicle. (NHTSA3)
School Bus Service	The operation of buses exclusively to carry school passengers to and from their schools. (FTA1)
School Buses	Type I and Type II school vehicles as defined in Highway Safety Program Standard No. 17, used exclusively to transport school students, personnel, and equipment. (FTA1)
School Bus-Related Crash	Any crash in which a vehicle, regardless of body design and used as a school bus, is directly or indirectly involved, such as a crash involving school children alighting from a vehicle.
Scow (Water)	Any flat-bottomed, nonself-propelled, rectangular vessel with sloping ends. Large scows are used to transport sand, gravel, or refuse.
Scrappage Rate	As applied to motor vehicles, it is usually expressed as the percentage of vehicles of a certain type in a given age class that are retired from use (lacking registration) in a given year. (DOE6)
Sea Level Engine	A reciprocating aircraft engine having a rated takeoff power that is producible only at sea level. (14CFR1)
Seabee	A type of barge carrying ship, similar to the LASH vessel except it employs a heavy-lift elevator at the stern-end of the ship to lift barges on and off. (MARAD1)
Seabee System	(See also Lighter-Aboard-Ship) Designed by Lykes Bros. Steamship Co., the system requires a SEABEE lighter or barge and a SEABEE carrier vessel or mother ship. The barges are 97.5 feet long and 35 feet side and have a hatch opening of 85 by 35 feet. The barges are moved down the inland waterway to the mother ship and brought on board by a 2,000-ton immersible elevator which is an integral part of the mother ship. Wheel dollies then transport the barges from the elevator to the point of rest on the ship. (TNDOT1)
Sea-Bee Vessels	Ocean vessels constructed with heavy-duty submersible hydraulic lift or elevator system at the stern of the vessel. The Sea-Bee system facilitates forward transfer and positioning of barges. (MARAD2)
Sea-Land Barge	Barge designed as a container that can be moved directly from the inland waterway to a truck or train and then moved to destination. (TNDOT1)
Seaplane Base	Facility used primarily by seaplanes. (DOI3)
Seaplane Landing/Take-Off	Water area used for seaplanes landing and takeoff. (DOI3)
Search	The effort expended to locate a distressed unit by a reporting unit in terms of time and distance. (USCG3)
Search and Rescue (SAR)	(See also SAR Facility) A service which seeks missing aircraft and assists those found to be in need of assistance. It is a cooperative effort using the facilities and services of available Federal, state, and local agencies. (FAA8)
Seat Offered Kilometer	Unit of measure representing the movement over one kilometer or one seat available in an Inland Waterways Transport (IWT) passenger vessel when performing the services for which it is primarily intended over one kilometer. (TNDOT1)
Seating Capacity	The number of seats that are actually installed in the vehicle. (FTA1)
Seating Position	The location of the occupants in the vehicle. More than one can be assigned the same seat position; however, this is allowed only when a person is sitting on someone's lap. (NHTSA3)
Seating Reference Point (SGRP)	The unique design H-point, as defined in Society of Automotive Engineers (SAE) J1100 (June 1984), which 1) Establishes the rearmost normal design driving or riding position of each designated seating position, which includes consideration of all modes of adjustment, horizontal, vertical, and tilt in a vehicle; 2) Has X, Y, and Z coordinates, as defined in SAE J1100 (June 1984), established relative to the designed vehicle structure; 3) Simulates the position of the pivot center of the human torso and thigh; and 4) Is the reference point employed to position the two-dimensional drafting template with the 95th percentile leg described in SAE J826 (May 1987), or, if the drafting template with the 95th percentile leg cannot be positioned in the seating position, is located with the seat in its most rearward adjustment position. (49CFR571)
Seat-Miles	The aircraft miles flown in each inter-airport hop multiplied by the number of seats available on that hop for revenue passenger use. (FAA11)
Second In Command	A pilot who is designated to be second in command of an aircraft during flight time. (14CFR1)
Secondary Airport	An airport receiving approach control service as a satellite to a primary approach control facility, or one at which control is exercised by the approach control facility under tower en route control procedure. (FAA14)
Secondary Separation Assurance	A backup to the primary means for maintaining aircraft separation. (FAA7)
Section 15	See National Transit Database.
Section Modulus	A measure of the strength of frame side rails, determined by the cross-section area and shape of the side rails. Section modulus is not affected by the material from which the side rail is made, only by the shape and position of the rail. (TII1) (TII2)
Sectional Aeronautical Charts	Designed for visual navigation of slow or medium speed aircraft. Topographic information on these charts features the portrayal of relief and a judicious selection of visual check points for Visual Flight Rules (VFR) flight. Aeronautical information includes visual and radio aids to navigation, airports, controlled airspace, restricted areas, obstructions and related data. (FAA4)
Sectionalizing Switch	A switch for disconnecting a section of a power line from the source of energy. (49CFR236)
Sector Suite (S/S)	Refers to the composition of functions which directly comprise either the Controller or Sector Suite Console/Support processing elements. (FAA8)
Sector Suite Work Station	A group of consoles containing displays and input devices whereby Air Traffic Control (ATC) Specialists, Controllers or Supervisors interface with the ACF. (FAA8)
Self-Propelled Barge	Freight vessel having its own means of mechanical propulsion. (TNDOT1)
Self-Propelled Pusher Barge	Self-propelled barge designed or fitted to push pushed or pushed-towed barges. (TNDOT1)
Self-Propelled Pusher Tanker Barge	Self-propelled pusher barge for the bulk transport of liquids or gases. (TNDOT1)
Self-Propelled River-Sea Navigation Vessel	Inland Waterways Transport (IWT) freight vessel having a carrying capacity of at least 20 tons also designed for the transport of goods by sea and equipped with their own means of propulsion developing at least 37 kilowatts (KW). (TNDOT1)
Self-Propelled Tanker Barge	Self-propelled barge intended for the bulk transport of liquids or gases. (TNDOT1)
Self-Propelled Vessel	A vessel that has its own means of propulsion. Includes tankers, containerships, dry bulk cargo ships, and general cargo vessels.
Semaphore Arm	The part of a semaphore signal displaying an aspect. It consists of a blade fastened to a spectacle. (49CFR236)
Semaphore Arm Spectacle	That part of a semaphore arm which holds the roundels and to which the blade is fastened. (49CFR236)
Semaphore Blade	The extended part of a semaphore arm which shows the position of the arm. (49CFR236)
Semi	(See also Semitrailer, Tractor-Semitrailer, Truck) Semitrailer, used loosely in reference to tractor and semitrailer unit. (ATA1)
Semitrailer	Any motor vehicle, other than a pole trailer, which is designed to be drawn by another motor vehicle and so constructed so that some part of its weight rests upon or is carried by the self-propelled towing vehicle. (49CFR390) (49CFR571)
Serious Injury	An injury that results in the amputation of any appendage, the loss of sight in an eye, the fracture of a bone, or the confinement in a hospital for a period of more than 24 consecutive hours. (49CFR229)
Serious Injury (Air Carrier/General Aviation)	An injury that requires hospitalization for more than 48 hours, commencing within 7 days from the date when the injury was received; results in a bone fracture (except simple fractures of fingers, toes, or nose); involves lacerations that cause severe hemorrhages, or nerve, muscle, or tendon damage; involves injury to any internal organ; or involves second- or third-degree burns or any burns affecting more than 5 percent of the body surface.
Serious Traffic Violation	Conviction, when operating a commercial motor vehicle, of 1) Excessive speeding, involving any single offense for any speed of 15 miles per hour or more above the posted speed limit; 2) Reckless driving, as defined by State or local law or regulation, including but not limited to offenses of driving a commercial motor vehicle in willful or wanton disregard for the safety of persons or property; 3) Improper or erratic traffic lane changes; 4) Following the vehicle ahead too closely; or 5) A violation, arising in connection with a fatal accident, of State or local law relating to motor vehicle traffic control other than a parking violation. (Serious traffic violations exclude vehicle weight and defect violations.) (49CFR383)
Service Brake	The primary mechanism designed to stop a motor vehicle. (49CFR571)
Service Brake System	A primary brake system used for slowing and stopping a vehicle. (49CFR393)
Service Consumed	The amount of service actually used by passengers which is measured by unlinked passenger trips and passenger miles. (FTA1)
Service Vehicles	The floating and rolling stock used in connection with keeping the revenue vehicles in operation. (FTA1)
Set	Current or eddies that are not flowing in the natural direction. An opposite current or eddy that tends to counteract the forward movement of a tow or vessel. (TNDOT1)
Set (Of Current)	Deviation from normal current flow, caused by some obstruction such as pier, wall, sandbar, etc. For example, current set above some lock approaches due to flow of water through dam gates. (TNDOT1)
Set (Tow)	A sideways movement of the tow caused by the current or wind. The set of the tow can be very important when the tow meets another tow in close quarters. (TNDOT1)
Set It Down	To stop quickly. (ATA1)
Set Over	Movement of a dredge to allow vessels clear passage in a channel. Also, the arrangement of a tow in a lock whereby one barge is moved up abreast of the main body of a tow. (TNDOT1)
Sevice Supplied	The amount of service actually made available to prospective passengers. Service supplied is measured in vehicles, miles and/or hours that were operated. (FTA1)
Shag	Small, city trailer. (ATA1)
Shake the Lights	Blinking headlights as a warning signal. (ATA1)
Shake Up a Reef	To drive the tow at a sufficient speed to create a wake which, when it reaches a suspicious area, will cause the appearance of the reef to show by the turbulence. (TNDOT1)
Shaping Out Reef or Shore	Channel report term meaning steering tow so as to follow the contour of shore or reef. (TNDOT1)
Shaping Up	Getting tow in position to run crossing or bridge. (TNDOT1)
Shared Roadway	Any roadway upon which a bicycle lane is not designated and which may be legally used by bicycles regardless of whether such facility is specifically designated as a bikeway. (23CFR217)
Sheathing	A covering consisting of a smooth layer of wood placed over metal and secured to prevent any movement. (49CFR171)
Sheep Herder	Driver with questionable ability. (ATA1)
Sheer Boom	Same purpose as sheer fence, but a floating structure. (TNDOT1)
Sheer Fence	A series of pilings with tinted lattice-work attached, extending from bridge piers upstream and downstream to assist the navigator in passing through the narrow bridge spans without damage to the bridge or piers or the vessel. Usually found at bridges that are lift, swing, or bascule types. (TNDOT1)
Shifting Bar	A sandbar which moves under the influence of current, usually gradually down river. It may also shift from one side of the river to the other. A sunken log or tree or deep hole in the channel can cause current changes which will build up a bar even above or below the area. (TNDOT1)
Shipper's Export Declaration	A form required by the United States government for the compilation of statistics on trade both with foreign countries and with United States territories and possessions. It is necessary on practically every commercial shipment leaving the United States with the exception of mail shipments of small value. (TNDOT1)
Shipping Paper	A shipping order, bill of lading, manifest or other shipping document serving a similar purpose and containing the information required by 49 CFR 172.202, 172.203, and 172.204. (49CFR171)
Ship's Manifest	A list, signed by the captain of a ship, of the individual shipments constituting the ship's cargo. (USTTA1)
Ship's Tackle	All rigging, etc., utilized on a ship to load or discharge cargo. (TNDOT1)
Shipyard	A yard or area where ships are built or repaired. (DOI4)
Shoal	1) Shallow; 2) To grind a boat on the bottom; 3) A sandbank or sandbar formed by river currents. (TNDOT1)
Shore	That part of the land in immediate contact with a body of water including the area between high and low water lines. (DOI4)
Shoreline	The line of contact between a body of water and the land. (DOI4)
Short Cut	A course different from the customary one taken by a pilot. (TNDOT1)
Short sea Shipping	Also known as coastal or coastwise shipping, describes marine shipping operations between ports along a single coast or involving a short sea crossing.
Short Ton	A unit of weight equal to 2,000 pounds. (DOE3) (DOE5)
Shortline Railroad	Freight railroads which are not Class I or Regional Railroads, that operate less than 350 miles of track and earn less than $40 million.
Shoulder	An area adjacent to the edge of paved runways, taxiways, or aprons providing a transition between the pavement and the adjacent surface; support for aircraft running off the pavement; enhanced drainage; and blast protection. (FAA12)
Shoveling	Improper loading of freight. (ATA1)
Shunt	(See also Switch Shunting Circuit) A by-path in an electrical circuit. (49CFR236)
Shunt Fouling Circuit	(See also Switch Shunting Circuit) The track circuit in the fouling section of a turnout, connected in multiple with the track circuit in the main track. (49CFR236)
Shunt Wire	A wire forming part of a shunt circuit. (49CFR236)
Shut In	Closed temporarily; wells and mines capable of production may be shut in for repair, cleaning, inaccessibility to a market, etc. (DOE5)
Shuttle	A public or private vehicle that travels back and forth over a particular route, especially a short route or one that provides connections between transportation systems, employment centers, etc. (APTA1)
Sick Horse	A tractor in poor mechanical condition, especially with low power. (ATA1)
Side Collision	A collision at a turnout where one consist strikes the side of another consist. (FRA2)
Side Extremities	The outermost point on the sides of the vehicle. Nonstructural protrusions such as tail lights, hinges, and latches are excluded from the determination of the outermost point. (49CFR393)
Side Facing Glazing Location	Any location where a line perpendicular to the plane of the glazing material makes an angle of more than 50 degrees with the centerline of the locomotive, caboose or passenger car. (49CFR223)
Side Line	Lashing used to hold two barges side by side. (TNDOT1)
Side Marker Lamp (Intermediate)	A lamp shown to the side of a trailer to indicate the approximate middle of a trailer 30 feet or more in length. (49CFR393)
Side Marker Lamps	Lamps used on each side of a trailer to indicate its overall length. (49CFR393)
Sideswipe Collision	A collision of two vehicles in which the sides of both vehicles sustain minimal engagements. (NHTSA3)
Siding	An auxiliary track for meeting or passing trains. (49CFR236) (FRA2)
Siding/Spur Railway	Track connected with the primary track, sometimes leading to a production or storage site, and used for passing, temporary storage, or loading and unloading of railway cars. (DOI3)
Sightseeing Operations	Special service involving the transportation of passengers assembled into a travel group by the carrier and specifically designed to service some special purpose beyond mere public transportation. Such special service is to be distinguished from service which solely contemplates expeditious service between fixed points on a fixed route according to a predetermined schedule. (FTA1)
Sign	A roadway-associated feature which provides information to people passing. (DOI4)
Significant Meteorological Convective (SIGMET) Information	A weather advisory concerning convective weather significant to the safety of all aircraft. Convective SIGMETs are issued for tornadoes, lines of thunderstorms, embedded thunderstorms of any intensity level, areas of thunderstorms greater than or equal to level 4 with an area coverage of 4/10 (40%) or more, and hail 3/4 inch or greater. (FAA4)
Sill	A horizontal beam forming the bottom of an entrance to a lock. (TNDOT1)
Single	A particular lockage of a tow, used when the tow is too long to enter the lock chamber and must be uncoupled. The towboat, and possibly one other barge, must move up alongside the forward part of the tow to lock through the entire tow at one time or in one lockage. (TNDOT1)
Single Axle Weight	The total weight transmitted to the road by all wheels whose centers may be included between two parallel transverse vertical planes 40 inches apart, extending across the full width of the vehicle. The Federal single axle weight limit on the Interstate System is 20,000 pounds. (23CFR658)
Single Packaging	A non-bulk packaging other than a combination packaging. (49CFR171)
Single Set Over	See Knockout Single.
Single Trailer Five Axle Truck	All five-axle vehicles consisting of two units, one of which is a tractor or straight truck power-unit. (FHWA2)
Single Trailer Four or Less Axle Truck	All vehicles with four-or-less axles consisting of two units, one of which is a tractor or straight truck power-unit. (FHWA2)
Single Trailer Six or More Axle Truck	All vehicles with six-or-more axles consisting of two units, one of which is a tractor or straight truck power-unit. (FHWA2)
Single Unit Four or More Axle Truck	All vehicles on a single frame with four-or-more axles. (FHWA2)
Single Unit Four Tire Vehicle	All two-axle, four-tire vehicles, other than passenger cars. Included in this classification are pickups, panels, vans and other vehicles such as campers, motor homes, ambulances, hearses, and carryalls. other two-axle, four-tire single-unit vehicles pulling recreational or other light trailers are included in this classification. (FHWA2)
Single Unit Six Tire Two Axle Truck	All vehicles on a single frame including trucks, camping and recreational vehicles, motor homes, etc., having two axles and dual rear wheels. (FHWA2)
Single Unit Three Axle Truck	All vehicles on a single frame including trucks, camping and recreational vehicles, motor homes, etc., having three axles. (FHWA2)
Single Unit Truck	Includes two-axle, four-tire trucks and other single unit trucks. (DOE6)
Single-Unit Truck	A medium or heavy truck in which the engine, cab, drive train, and cargo area are all one chassis. (NHTSA3) (NHTSA4)
Sink/Rise	The place at which a stream disappears underground or reappears at the surface in a karst area. (DOI3)
Sinking	(See also Swamping) Losing enough buoyancy to settle below the surface of the water. (USCG2)
Siphon	Designed to convey water by gravitational force over, or under, an obstruction. (DOI3)
Six Banger	Six-cylinder engine. (ATA1)
Skiff	A small, hand-propelled rowboat. Sometimes called a "yawl." (TNDOT1)
Skinnie Axle	Six axle trailer. (ATA1)
Skins	Tires. (ATA1)
Sleeper	Truck cab with a sleeping compartment. (ATA1)
Sleeping Sawyer	A submerged heavy timber hazardous to the vessel. (TNDOT1)
Slew	See Slough.
Slide	A water borne skid of a tow to momentum and current (encountered downbound only). (TNDOT1)
Sliding	Uncontrolled sideways movement of vessel. (TNDOT1)
Slip Line	A line around timberhead so arranged that one end may be released while boat, is backing away from dock. (TNDOT1)
Slip Resistant Material	Any material designed to minimize the accumulation of grease, ice, mud or other debris and afford protection from accidental slipping. (49CFR399)
Slip-Seat	Relay operation where drivers are changed periodically, but the truck continues from origin to destination. (ATA1)
Slotted Mechanical Signal	A mechanically operated signal with an electromagnetic device inserted in its operating connection to provide a means of controlling the signal electrically, as well as mechanically. (49CFR236)
Slough	Generally non-navigable parts of the river where it runs behind islands and away from the channel. (Pronounced "slew"). (TNDOT1)
Slow Speed	A speed not exceeding 20 miles per hour. (49CFR236)
Small Air Traffic Hub	A community enplaning from 0.05 to 0.24 percent of the total enplaned passengers in all services and all operations for all Communities within the 50 States, the District of Columbia, and other U.S. areas designated by the Federal Aviation Administration. (FAA2) (FAA14) (FAA15)
Small Aircraft	An aircraft of 12,500 pounds or less maximum certificated takeoff weight. (14CFR1)
Small Certificated Air Carrier	An air carrier holding a certificate issued under section 401 of the Federal Aviation Act of 1958, as amended, that operates aircraft designed to have a maximum seating capacity of 60 seats or fewer or a maximum payload of 18,000 pounds or less.
Small Certified Air Carrier	Air carrier holding a certificate issued under section 401 of the Federal Aviation Act of 1958 and operating aircraft designed to have a maximum seating capacity of 60 or less seat or a maximum payload of 18,000 pounds or less. (FAA2)
Small Particulate Matter (PM-10)	Particulate matter which is less than 10 microns in size. A micron is one millionth of a meter. Particulate matter this size is too small to be filtered by the nose and lungs.
Small Urban Area	Places of 5,000 to 49,999 urban population (except in the case of Maine and New Hampshire) outside of urbanized areas. As a minimum the small urban area includes any place containing an urban population of 5,000 or more as designated by the U.S. Bureau of the Census. (FHWA2)
Smart Growth	A set of policies and programs design to protect, preserve, and economically develop established communities and valuable natural and cultural resources.
Smoke Him	Pass another vehicle. (ATA1)
Smoker	Tractor emitting excessive smoke from exhaust. (ATA1)
Smokestack	Vertical exhaust pipe on side of cab. (ATA1)
Snag	A stem or trunk of a tree above the surface of the water. (DOI4)
Snag/Stump Area	An area identified as a danger to maritime navigation containing one or more trunks or stems near the surface of the water. (DOI3)
Snowmobile	A motorized vehicle solely designed to operate on snow or ice. (23CFR217)
Snub Nose	See Cab Over.
Solar Energy	The radiant energy of the sun, which can be converted into other forms of energy, such as heat or electricity. (DOE3) (DOE5)
Solid	A material which has a vertical flow of two inches (50 mm) or less within a three-minute period, or a separation of less than one gram (18) of liquid when determined in accordance with the procedures specified in American Society for Testing and Materials (ASTM) D 4359, "Standard Test Method for Determining Whether a Material is a Liquid or Solid." (49CFR171)
Solid Bluff Reef	A shallow reach with deep water below it, not too much current, and in which the sand is pretty well packed. (TNDOT1)
Solution	Any homogeneous liquid mixture of two or more chemical compounds or elements that will not undergo any segregation under conditions normal to transportation. (49CFR171)
Sooging	River term used when scrubbing any part of the boat. (TNDOT1)
Sortie	Action of a unit's resource in rendering assistance, or use of personnel on Communication/Harbor checks. Each action comprises one sortie. (USCG3)
Sounding Pole	(See also Pike Pole) A pole generally 20 feet long, lightweight, and painted with alternating red, white, and black colors at one foot intervals to permit easy reading of water depths. (TNDOT1)
Sources	Refers to the origin of air contaminants. Can be point (coming from a defined site) or non-point (coming from many diffuse sources).[Stationary sources include relatively large, fixed facilities such as power plants, chemical process industries, and petroleum refineries. Area sources are small, stationary, non-transportation sources that collectively contribute to air pollution, and include such sources as dry cleaners and bakeries, surface coating operations, home furnaces, and crop burning. Mobile sources include on-road vehicles such as cars, trucks, and buses; and off-road sources such as trains, ships, airplanes, boats, lawnmowers, and construction equipment.
Space Vehicle	An artificial body operating in outer space (beyond the earth's atmosphere.) (AIA1)
Spar Her Out	Usually to hold a boat off bank using a heavy timber. (TNDOT1)
Spare Parts, Supplies and Other-Net	Flight equipment replacement parts of a type recurrently expended and replaced rather than repaired or reused, supplies such as unissued fuel inventories and unissued materials and supplies held in stock, prepaid items, net investments in direct financing and sales type leases and other current assets. Spare parts may be reduced by an allowance for obsolescence to provide for losses in value. (BTS4)
Spare Vehicles	The revenue vehicles available to the transit agency to accommodate routine and heavy maintenance requirements, as well as unexpected vehicle breakdowns or accidents, while preserving schedules service operations. (FTA1)
Special Fuels	Consist primarily of diesel fuel with small amount of liquified petroleum gas, as defined by the Federal Highway Administration. (DOE6)
Special Purpose Terminal	A specialized terminal designed to handle one type of commodity. It is a transfer facility with little or no manufacturing, although it might include lending, separating, and similar processing activities. (TNDOT1)
Special Purpose Vehicle	A motor vehicle commercially designed for some purpose other than the transportation of personnel, supplies, or equipment. This definition excludes any motor vehicle designed for transport and modified locally as an expedient for meeting special needs; e.g., a pickup with a snowplow blade attached. (GSA2)
Special Use Airspace	Airspace of defined dimension identified by an area on the surface of the earth wherein activities must be confined because of their nature and/or where limitations may be imposed on aircraft operations that are not a part of those activities. (FAA8)
Special Use Zone	An area where distinctive types of shipping activities occur. (DOI3)
Special Vehicle	Consists of the following types of vehicles; snowmobile, farm equipment other than trucks, dune buggy or swamp buggy, construction equipment other than trucks, ambulance, large limousine, self propelled camper and motor home, fire truck, other special vehicles. (NHTSA1)
Special Visual Flight Rules (VFR) Conditions	Meteorological conditions that are less than those required for basic Visual Flight Rules (VFR) flight in controlled airspace and in which some aircraft are permitted flight under visual flight rules. (14CFR1)
Special Visual Flight Rules (VFR) Operations	Aircraft operating in accordance with clearances within controlled airspace in meteorological conditions less than the basic Visual Flight Rules (VFR) weather minimum. Such operations must be requested by the pilot and approved by ATC. (14CFR1)
Special Warehousing and Storage	Establishments primarily engaged in the warehousing and storage of special products, not elsewhere classified, such as household goods, automobiles (dead storage only), furs (for the trade), textiles, whiskey, and goods at foreign trade zones. (BOC1)
Specialist	The internal individual or group who provides service through the National Air Space (NAS) (e.g., controllers, engineers, maintenance and management personnel). (FAA8)
Specialized Carrier	A trucking company franchised to transport articles which, because size, shape, weight, or other inherent characteristics, require special equipment for loading, unloading or transporting. (ATA2)
Specialty Ship (Liquefied Petroleum Gas/Liquefied Natural Gas)	A ship designed specifically to carry liquefied gases. (DOE5)
Specific Acceleration Power	Measured in watts per kilogram. Acceleration power is divided by the battery system weight. Weight must include the total battery system. (DOE6)
Specific Energy	Measured in watt hours per kilogram. The rated energy capacity of the battery divided by the total battery system weight. (DOE6)
Specific Public Transportation	Transportation by bus, rail, or any other conveyance (other than aircraft) provided by a private entity to the general public, with general or special service (including charter service) on a regular and continuing basis. (49CFR37)
Specified Minimum Yield Strength	(See also Stress Level) The minimum yield strength, expressed in pounds per square inch, prescribed by the specification under which the material is purchased from the manufacturer. (49CFR194) (49CFR195)
Speed Attainable In 1 Mile	The speed attainable by accelerating at maximum rate from a standing start for 1 mile, on a level surface. (49CFR571)
Speed Attainable In 2 Miles	The speed attainable by accelerating at maximum rate from a standing start for 2 miles, on a level surface. (49CFR571)
Speeding	Operating at a speed, possibly below the posted limit, above that which a reasonable and prudent person would operate under the circumstances. (USCG2)
Spike	One barge that is wired to head of tow that is 2 or 3 barges wide. (TNDOT1)
Spillway	A constructed passage for surplus water to run over or around a dam. (DOI3)
Spillway Elevation	The stage of an artificially impounded water body as determined by the spillway. (DOI3)
Spillway Section of a Dam	That portion of a dam through which water flows; does not permit navigation. (TNDOT1)
Spin Out	Lose traction on slippery roadway. (ATA1)
Spine Car	An articulated five-platform railcar. (MARAD2)
Splitting On the Heads	Term describing the situation when a towboat is faced up to the center of two strings of barges. (TNDOT1)
Sponsor	Any private owner of a public-use airport or any public agency (either individually or jointly with other public agencies) that submit to the Secretary of Transportation, in accordance with the Airport & Airway Improvement Act of 1982, an application for financial assistance. (FAA2)
Spoonbill Barge	A 50 foot wide barge with a very long rake, usually about 60 feet. (TNDOT1)
Sport-Utility Vehicle	Includes light trucks that are similar to jeeps. Other common terms for these vehicles are sport-utility, special purpose, utility or off-the-road vehicles. They may have a four or two-wheel drive. Previously called Jeep-Like Vehicle. (DOE4)
Spot Market	Buying and selling of fuel for immediate or very near-term delivery by contracts to meet peak demands. (DOE5)
Spot the Body	Part of a trailer. (ATA1)
Spotter	(See also Yardbird) Terminal yard driver who parks vehicles brought in by regular drivers, also a supervisor who observes the activities of drivers on the road. (ATA1)
Sprawl	Urban form that connotatively depicts the movement of people from the central city to the suburbs. Concerns associated with sprawl include loss of farmland and open space due to low-density land development, increased public service costs, and environmental degradation as well as other concerns associated with transportation.
Spring	A place where water issues from the ground naturally. (DOI4)
Spring Line	A line to hold boat from running upstream. Used in mooring, crossing one another. Also called "backing line". (TNDOT1)
Spring Switch	A switch equipped with a spring device which forces the points to their original position after being trailed through and holds them under spring compression. (49CFR236)
Spud	The heavy timber or pipe extending vertically through a well in the bottom of the boat used for mooring in lieu of anchors on riverboats. (TNDOT1)
Spud Barge	A barge utilizing spuds for mooring. Used as a work barge or loading and unloading platform. (TNDOT1)
Squealer	Also known as "tattle tale" whose proper name is tachograph. A device used in a cab to automatically record miles driven, number of stops, speed and other factors during a trip. (ATA1)
Stabilized Channel	A channel which remains in one location permanently with no maintenance. (TNDOT1)
Stack	Exhaust pipe on diesel. (ATA1)
Stack Car	An articulated five-platform rail car that allows containers to be double stacked. (MARAD2)
Stacktrain	A rail service whereby rail cars carry containers stacked two-high on specially-operated unit trains. (MARAD2)
Stage 2 Aircraft	An aircraft that has been shown to comply with the stage 2 noise requirements under Federal Aviation Regulation (FAR) Part 36. (Examples include the B-727-200, DC-9, and BAC-111.) (FAA3)
Stage 3 Aircraft	An aircraft that has been shown to comply with the quieter Stage 3 noise requirements under Federal Aviation Regulation (FAR) Part 36 (Examples include the B-737-300, B-757, MD-80, and A- 310.) (FAA3)
Stake Body	Truck or trailer platform body with readily removable stakes, which may be joined by chains, slats, or panels. (ATA1)
Stakeholder	Person or goup affected by a transportation plan, program or project. Person or group believing that are affected by a transportation plan, program or project. Residents of affected geographical areas.
Stakeholders	Individuals and organizations involved in or affected by the transportation planning process. Include federal/state/local officials, MPOs, transit operators, freight companies, shippers, and the general public.
Standard	Prescribes design constraints or performance requirements for boats and/or associated equipment. May be either a regulation or may be voluntary. (USCG1)
Standard Barge	A barge which is approximately 26 feet wide and 175 feet long and either open or covered. (TNDOT1)
Standard Body	A body type normally furnished as a standard option by the original equipment (chassis) manufacturer (e.g., pick-up, panel, and flat bed). (GSA2)
Standard Design Vehicle	A vehicle procurable from regular production lines. Included in this category are commercial design vehicles modified for special purpose use, if the modifications have not altered the basic design characteristics of the vehicle. (GSA2)
Standard Industrial Classification (SIC)	A set of codes developed by the Office of Management and Budget which categorizes industries into groups with similar economic activities. (DOE3)
Standard Instrument Department (SID) Charts	Designed to expedite clearance delivery and to facilitate transition between takeoff and en route operations. Each SID procedure is presented as a separate chart and may serve a single airport or more than one airport in a given geographical location. (FAA4)
Standard Labor Rate	A rate calculated to approximate the total per hour cost of salaries and related fringe benefits for application against labor hours in pricing job orders. (GSA2)
Standard Metropolitan Statistical Area	(See also Central City, Metropolitan Statistical Area) A county that contains at least one city of 50,000 population, or twin cities with a combined population of at least 50,000, plus any contiguous counties that are metropolitan in character and have similar economic and social relationships. (FAA4) (FAA15)
Standard Railway Gauge	Distance between the rails of a track of 4 ft 8.5 inches. (DOI3)
Standard Size Bus	A bus from 35 to 41 feet in length. (APTA1)
Standard Terminal Arrival (STAR) Route Charts	Designed to expedite air traffic control arrival procedures and to facilitate transition between en route and instrument approach operations. Each STAR procedure is presented as a separate chart and may serve a single airport or more than one airport in a given geographical location. (FAA4)
Standing Capacity	The number of standing passengers that can be accomodated aboard the revenue vehicle during a normal full load (non-crush) in accordance with established loading policy or, in absence of a policy, the manufacturer's rated standing capacity figures. (FTA1)
Standout	Term used when the channel runs down the shape of shore and there is an obstruction along the set of marks running out into the middle of the river, thus requiring a temporary change of course to clear. (TNDOT1)
Starboard	The right side of a ship when facing the bow. (MARAD2)
State	As defined in chapter 1 of Title 23 of the United States Code, any of the 50 States, comprising the United States, plus the District of Columbia and the Commonwealth of Puerto Rico. However, for some purposes (e.g., highway safety programs under 23 U.S.C. 402), the term may also include the Territories (the U.S. Virgin Islands, Guam, American Samoa, and the Northern Mariana Islands) and the Secretary of the Interior (for Indian Reservations). For the purposes of apportioning funds under sections 104, 105, 144, and 206 of Title 23, United States Code, the term "State" is defined by section 1103(n) of the TEA-21 to mean any of the 50 States and the District of Columbia.
State And Local Highway Expenditures	Disbursements for capital outlays, maintenance and traffic surfaces, administration and research, highway law enforcement and safety, and interest on debt.
State Implementation Plan (SIP)	Produced by the state environmental agency, not the MPO. A plan mandated by the CAA that contains procedures to monitor, control, maintain, and enforce compliance with the NAAQS. Must be taken into account in the transportation planning process.
State Infrastructure Bank (SIB)	A revolving fund mechanism for financing a wide variety of highway and transit projects through loans and credit enhancement. SIBs are designed to complement traditional Federal-aid highway and transit grants by providing States increased flexibility for financing infrastructure investments.
State of Domicile	That state where a person has his/her true, fixed, and permanent home and principal residence and to which he/she has the intention of returning whenever he/she is absent. (49CFR383)
State Planning and Research Funds (SPR)	Primary source of funding for statewide long-range planning.
State Routing Agency	An entity (including a common agency of more than one state such as one established by Interstate compact) which is authorized to use state legal process pursuant to 49 CFR 177.825 to impose routing requirements, enforceable by State agencies, on carriers of radioactive materials without regard to intrastate jurisdictional boundaries. This term also includes Indian tribal authorities which have police powers to regulate and enforce highway routing requirements within their lands. (49CFR171)
State Transportation Agency	The State highway department, transportation department, or other State transportation agency to which Federal-aid highway funds are apportioned. (23CFR420)
State Transportation Improvement Program (STIP)	A staged, multi-year, statewide, intermodal program of transportation projects, consistent with the statewide transportation plan and planning processes as well as metropolitan plans, TIPs, and processes.
State-Designated Route	A preferred route selected in accordance with U.S. DOT "Guidelines for Selecting Preferred Highway Routes for Highway Route Controlled Quantities of Radioactive Materials" or an equivalent routing analysis which adequately considers overall risk to the public. (49CFR171)
Statewide Comprehensive Outdoor Recreation Plan (SCORP)	A statewide recreation plan required by the Land and Water Conservation Fund Act of 1965. Addresses the demand for and supply of recreation resources (local, State, and Federal) within a State, identifies needs and new opportunities for recreation improvements, and sets forth an implementation program to meet the goals identified by its citizens and elected leaders. [National Park Service] NOTE: Metropolitan and statewide transportation plans plans should be coordinated with SCORPs.
Statewide Transportation Plan	The official statewide intermodal transportation plan that is developed through the statewide transportation planning process.
Static Loaded Radius Arc	A portion of a circle whose center is the center of a standard tire-rim combination of an automobile and whose radius is the distance from that center to the level surface on which the automobile is standing, measured with the automobile at curb weight, the wheel parallel to the vehicle's longitudinal centerline, and the tire inflated to the manufacturer's recommended pressure. (49CFR523)
Station	With respect to intercity and commuter rail transportation, the portion of a property located appurtenant to a right of way on which intercity or commuter rail transportation is operated, where such portion is used by the general public and is related to the provision of such transportation, including passenger platforms, designated waiting areas, rest rooms and, where a public entity providing rail transportation owns the property, concession areas, to the extent that such public entity exercises control over the selection, design, construction, or alteration of the property, but this term does not include flag stops (i.e., stations which are not regularly scheduled stops but at which trains will stop to board or detrain passengers only on signal or advance notice). (49CFR37)
Stationary Source	Relatively large, fixed sources of emissions (i.e. chemical process industries, petroleum refining and petrochemical operations, or wood processing).
Steamboat Gothic	An elaborately ornamental architectural style that is an imitation of river steamboats of the middle 19th century on the Ohio and Mississippi rivers. (TNDOT1)
Steamboat Jack	Colloquial term for an oversized turnbuckle with large pelican hooks on each end and a ratchet (handle) around the body used for tightening wire lashings and making up tows. Used to connect barges in tow. (TNDOT1)
Steamship Agent	A duly appointed and authorized representative in a specified territory acting in behalf of a steamship line or lines and attending to all matters relating to the vessels owned by his principals. (TNDOT1)
Steamship Conference	Collective rate-making bodies for liner water carriers that serve the same trade route. (MARAD1)
Steel Hull	Hulls of sheet steel or steel alloy, not those with steel ribs and wood, canvas or plastic hull coverings. (USCG2)
Steel Tower	A skeleton steel tower type of structure used for lighted shore aids; used in multiples of 10-foot sections. (TNDOT1)
Steel Wheel	In rail systems, the specially designed cast or forged steel, essentially cylindrical element that rolls on the rail, carries the weight, and provides guidance for rail vehicles. The wheels are semipermanently mounted in pairs on steel axles and are designed with flanges and a tapered treat to provide for operation on track of a specific gauge. The wheel also serves as a brake drum on cars with on-tread brakes. (TRB1)
Steer It	To navigate a portion of the river without flanking maneuver. (TNDOT1)
Steering Wheel Lash	The condition in which the steering wheel may be turned through some part of a revolution without associated movement of the front wheels. (49CFR393)
Stem Winder	Hand-crank starter. (ATA1)
Stern	The end of a vessel, opposite of bow. (MARAD2)
Stern Line	Long quartering line. (TNDOT1)
Stern Line Talk	Supposedly factual information about anything, passed between river people, usually by a lockman chatting with deck hands handling lines during lockage. (TNDOT1)
Stevedore	A person or firm that contracts with a vessel's owner, agent or charter operator, or with the owner of the cargo, to load or unload a ship or barge in port. (MARAD1)
Stilling Basin	A structure at the outlet end of a spillway to help dissipate the energy of flowing water into the downstream channel in such a manner as to prevent damage to the dam or scour of the bed or banks of the channel. (TNDOT1)
Stinger-Steered Combination	A truck tractor semitrailer wherein the fifth wheel is located on a drop frame located behind and below the rear-most axle of the power unit. (23CFR658)
Stockholder's Equity	The aggregate interest of holders of the air carrier's stock in assets owned by the air carrier. (BTS4)
Stockyard	An enclosed area in which livestock are temporarily kept. (DOI4)
Stolport	An airport specifically designed for Short Take-off and Landing (STOL) aircraft, separate from conventional airport facilities. (FAA2)
Stop	As applied to mechanical locking, a device secured to a locking bar to limit its movement. (49CFR236)
Stop Lamps	Lamps shown to the rear of a motor vehicle to indicate that the service brake system is engaged. (49CFR393)
Stop-Indication Point	As applied to an automatic train stop or train control system without the use of roadway signals, a point where a signal displaying an aspect requiring a stop would be located. (49CFR236)
Stopping Distance	The maximum distance on any portion of any railroad which any train operating on such portion of railroad at its maximum authorized speed, will travel during a full service application of the brakes, between the point where such application is initiated and the point where the train comes to a stop. (49CFR236)
Stopway	A defined rectangular surface beyond the end of a runway prepared or suitable for use in lieu of runway to support an airplane, without causing structural damage to the airplane, during an aborted takeoff. (FAA12)
Storage Tank	A container for storing a hazardous fluid, including an underground cavern. (49CFR193)
Stowage	The act of placing hazardous materials on board a vessel. (49CFR171)
Straight Truck	Vehicle with the cargo body and tractor mounted on the same chassis. (ATA2)
Strategic Communications	Air Traffic Management (ATM) communications that are planned as much as a day or more in advance of delivery. (FAA7)
Strategic Highway Network (STRAHNET)	A network of highways which are important to the United States' strategic defense policy and which provide defense access, continuity, and emergency capabilities for defense purposes.
Strategic Petroleum Reserve (SPR)	Petroleum stocks maintained by the Federal Government for use during periods of major supply interruption. (DOE3) (DOE5)
Strategic Rail Corridor Network (STRACNET)	An interconnected and continuous rail line network consisting of over 38,000 miles of track serving over 170 defense installations.
Stray	A buoy adrift from its proper station. Strays may often be lodged in and amongst dikes, etc. Stray buoys can be particularly confusing in the rays of a searchlight at night. (TNDOT1)
Stream/River	A body of flowing water. (DOI3)
Streetcar	Another name for "light rail." (APTA1)
Streetcar/Trolley	Includes trolleys, streetcars, and cable cars. (FHWA3)
Streetcars	Relatively lightweight passenger railcars operating singly or in short trains, or on fixed rails in rights-of-way that are not always separated from other traffic. Streetcars do not necessarily have the right-of-way at grade crossings with other traffic.
Stress Level	(See also Specified Minimum Yield Strength) The level of tangential or hoop stress, usually expressed as a percentage of specified minimum yield strength. (49CFR194) (49CFR195)
String Out	See Mule Train.
Strip Her	Unloading the trailer. (ATA1)
Stroke	The distance traveled by a piston in a cylinder during 1/2 revolution of the crankshaft. (TII1) (TII2)
Strong Outside Container	The outermost enclosure which provides protection against the unintentional release of its contents under conditions normally incident to transportation. (49CFR171)
Struck By Boat or Propeller	Striking of a victim who is outside of the boat, but not necessarily a swimmer. (USCG2)
Student Pilot	A student pilot may not operate an aircraft that is carrying a passenger or that is carrying property for compensation or hire. (FAA2)
Sub-Allocation	An administrative distribution of funds from BIA Central Office down to the BIA area.
Submerged Stream	An old river course inundated by an impounded water body. (DOI3)
Subregional Port	Waterfront area which 1) Has place identity, by reason of association with an adjacent or nearby town or city; 2) Has at least three commercial terminals located within a reasonable distance of the general area; and 3) Is served by a major railroad and at least one major interstate or U.S. highway. (TNDOT1)
Subscribed and Unissued Stock	The par or stated value, or the subscription price in the case of stock without par or stated value, of legally enforceable subscriptions to the capital stock of the air carrier. (BTS4)
Subscription Bus	A commuter bus express service operated for a guaranteed number of patrons from a given area on a prepaid, reserved basis. (APTA1)
Subsidy	Revenues received from the United States Government for the performance of guaranteed essential air service to small communities and for losses incurred in forced service. Does not include revenues from the carriage of mail at service rates or the performance of other contractual services for the Government. (BTS4)
Substantial Damage	As stated in 49CFR 830.2, damage or structural failure which adversely affects the structural strength, performance, or flight characteristics of the aircraft, and which would normally require major repair or replacement of the affected component. This does not include engine failure, damage limited to an engine, bent fairings or cowling, dented skin, small punctured holes in the skin of the fabric, ground damage to rotor or propeller blades, damage to landing gear, wheels, tires, flaps, engine accessories, brakes, or wingtips. (NTSB1) (NTSB2)
Suburban Bus	A bus with front doors only, normally with high-backed seats, and without luggage compartments or restroom facilities for use in longer-distance service with relatively few stops. (APTA1)
Suburban Rail	Another name for "commuter rail." (APTA1)
Subway	1) That portion of a transportation system that is constructed beneath the ground surface, regardless of its method of construction. 2) An underground rail rapid transit system or the tunnel through which it runs. 3) In local usage, sometimes used for the entire rail rapid transit system, even if it is not all beneath the ground surface. 4) A pedestrian underpass. (TRB1)
Subway - Tunnel/Tube	Rail transit way below surface with a cover over the tunnel. Cut and cover, bored tunnel, underwater tubes, etc., are included. (FTA1)
Sucker Brakes	Vacuum brakes. (ATA1)
Suicide	A person ending his or her own life intentionally. This is a subset of Collision with People. (FTA2)
Summerstock	Operation Summerstock has been a major program over the past fifteen years where Search and Rescue stations in the Ninth District are augmented by Reserve personnel during the busy summer SAR season. (USCG3)
Superiority of Trains	The precedence conferred upon one train over other trains by train order or by reason of its class or the direction of its movement. (49CFR236)
Supplemental Air Carrier	An air carrier authorized to perform passenger and cargo charter services.
Supplies and Other Net Spare Parts	Flight equipment replacement parts of a type recurrently expended and replaced rather than repaired or reused, supplies such as unissued fuel inventories and unissued materials and supplies held in stock, prepaid items, net investments in direct financing and sales type leases and other current assets. Spare parts may be reduced by an allowance for obsolescence to provide for losses in value. (BTS4)
Surface Rights	Fee ownership in surface areas of land. Also used to describe a lessee's right to use as much of the surface of the land as may be reasonably necessary for the conduct of operations under the lease. (DOE5)
Surface Transportation Program (STP)	Federal-aid highway funding program that funds a broad range of surface transportation capital needs, including many roads, transit, sea and airport access, vanpool, bike, and pedestrian facilities.
Surge Pressure	Pressure produced by a change in velocity of the moving stream that results from shutting down a pump station or pumping unit, closure of a valve, or any other blockage of the moving stream. (49CFR195)
Surplus	Any excess personal property not required for the needs and the discharge of the responsibilities of any Federal agency, as determined by the Administrator of General Services. (GSA2)
Surplus Energy	Energy generated that is beyond the immediate needs of the producing system. This energy may be supplied by spinning reserve and sold on an interruptible basis. (DOE5)
Surveillance	The detection, location, and tracking of aircraft within National Airspace System (NAS) airspace for the purposes of control, separation, and identification. Surveillance systems are electronic in nature; visual methods are purposely excluded. In the case of dependent surveillance, the aircraft provides all flight information. Surveillance systems are differentiated as independent, independent cooperative, and dependent. (FAA8)
Swamper	A helper who rides with driver. (ATA1)
Swamping	(See also Sinking) Filling with water, particularly over the side, but retaining sufficient buoyancy to remain on the surface. (USCG2)
Swash	The mass of broken foaming water which rushes bodily up a beach as a wave breaks. (DOI4)
Swindle Sheet	Interstate Commerce Commission (ICC) log. (ATA1)
Swing Dog	A locking dog mounted in such a manner that it is free to rotate on a trunnion which is riveted to a locking bar. (49CFR236)
Switch Circuit Controller	A device for opening and closing electric circuits, operated by a rod connected to a switch, derail or movable-point frog. (49CFR236)
Switch In	To remove barges from the main tow and move them into an unloading or fleeting area. The switching is done by the switching tug. (TNDOT1)
Switch Out	To move barges from the unloading or fleeting area to the main tow. (TNDOT1)
Switch Providing Access	A switch which if traversed by rolling equipment could permit that rolling equipment to couple to the equipment being protected. (49CFR218)
Switch Shunting Circuit	(See also Shunt, Shunt Fouling Circuit) A shunting circuit which is closed through contacts of a switch circuit controller. (49CFR236)
Switch-and-Lock Movement	A device, the complete operation of which performs the three functions of unlocking, operating and locking a switch, movable-point frog or derail. (49CFR236)
Switching and Terminal Railroad	Railroad that provides pick-up and delivery services to line-haul carriers
Switching Boat	Tug used to move barges between the loading or fleeting area and the main tow. Usually has about 1350 horsepower. (TNDOT1)
Switching Service	A railway service performed under yard rules and regulations. It may involve the classification of cars according to commodity and destination; the assembling of cars for train movement; changing the position of cars for purposes of loading, unloading, and weighing; the placing of locomotives and cars for repair and storage; and the moving of equipment in connection with the carrier's work service not constituting a road movement. (AAR1)
Synchromesh Transmission	A transmission with mechanisms for matching up the gear speeds so that they can be shifted without clashing, eliminating need for double clutching. (TII1) (TII2)
System	Total operations of a carrier or carrier grouping including both domestic and international operations. (BTS5) (BTS6)
System Planning	Also known as integrated airport system planning it is the initial, as well as continuing development for planning purposes of information and guidance to determine the extent, type, nature, location, and timing of airport development needed in a specific area to establish a viable balanced, and integrated system of public-use airports. (FAA2)
System Security	All activities associated with providing security to transit patrons and securing transit property including supervision and clerical support. Includes patrolling revenue vehicles and passenger facilities during revenue operations; patrolling and controlling access to yards, buildings and structures; monitoring security devices; and, reporting security breaches. (FTA1)
Tack	Short for tachograph or tachometer. (ATA1)
Tactical Communications	Communications that are developed and delivered as part of the real-time ATM process. (FAA7)
Tag	The official U.S. Government motor vehicle license plate, District of Columbia license plate, or license plate of any State, Territory, or possession of the United States. (GSA2)
Tag Axle	A nonpowered vehicle axle that helps distribute the load. (TRB1)
Tail Lamps	Lamps used to designate the rear of a motor vehicle. (49CFR393)
Tailboard Artist	One who thinks he is a perfect driver. (ATA1)
Tailgate	The outlet of a natural gas processing plant where dry residue gas is delivered or redelivered for sale or transportation. (DOE5)
Tailgate (Lower Lock Gate)	A gate located at the downstream of a lock in the tailwater of a dam. (TNDOT1)
Tailgating	Driving too closely behind the vehicle ahead. (ATA1)
Tailwater	A term to indicate the depth of water above pool stage immediately below a dam when that dam is passing water in a non-sufficient amount to raise the stage of the water immediately below the dam. A term used primarily in the Upper Mississippi River area. (TNDOT1)
Tainter Gate	A large gate used to control the flow of water through or over a dam; such gates have a cylindrical surface with the convex side facing upstream. (TNDOT1)
Takeoff Distance Available (TODA)	The runway length available for takeoff plus the length of any remaining runway and/or clearway beyond the far end. (FAA12)
Takeoff Power	1) With respect to reciprocating engines, means the brake horsepower that is developed under standard sea level conditions, and under the maximum conditions of crankshaft rotational speed and engine manifold pressure approved for the normal takeoff, and limited in continuous use to the period of time shown in the approved engine specification; and 2) With respect to turbine engines, means the brake horsepower that is developed under static conditions at a specified altitude and atmospheric temperature, and under the maximum conditions of rotor shaft rotational speed and gas temperature approved for the normal takeoff, and limited in continuous use to the period of time shown in the approved engine specification. (14CFR1)
Takeoff Run Available (TORA)	The runway length declared available and suitable for the ground run of an airplane taking off. (FAA12)
Takeoff Safety	A referenced airspeed obtained after lift-off at which the required one-engine-inoperative climb performance can be achieved. (14CFR1)
Takeoff Thrust	With respect to turbine engines, means the jet thrust that is developed under static conditions at a specific altitude and atmospheric temperature under the maximum conditions of rotorshaft rotational speed and gas temperature approved for the normal takeoff, and limited in continuous use to the period of time shown in the approved engine specification. (14CFR1)
Talus	Slopes of broken rock debris on a mountainside. (DOI4)
Tandem	(See also Dual Drive Tandem) Semitrailer or tractor with two rear axles. (ATA1)
Tandem Axle	Two axles operated from a single suspension. (TII1)(TII2)
Tandem Axle Weight	The total weight transmitted to the road by two or more consecutive axles whose centers may be included between parallel transverse vertical planes space more than 40 inches and not more than 96 inches apart, extending across the full width of the vehicle. The Federal tandem axle weight limit on the Interstate System is 34,000 pounds. (23CFR658)
Tandem Wing	A configuration having two wings of similar span, mounted in tandem. (14CFR1)
Tank	A structure used for the storage of fluids. (DOI4)
Tank Barge	A large, flat-bottomed, non-selfpropelled, compartmented, decked-over barge used for all types of liquid cargo (petroleum, molasses, chemicals, etc). (TNDOT1)
Tank Car	A railroad car consisting of a large cylindrical container attached to the railcar truck and used to transport liquids in bulk. (FRA3)
Tank Farm	An installation used by gathering and trunk pipeline companies, crude oil producers, and terminal operators (except refineries) to store crude oil. (DOE5)
Tank Vehicle	Any commercial motor vehicle that is designed to transport any liquid or gaseous materials within a tank that is either permanently or temporarily attached to the vehicle or the chassis. Such vehicles include, but are not limited to, cargo tanks and portable tanks, as defined in 49 CFR 171. However, this definition does not include portable tanks having a rated capacity under 1,000 gallons. (49CFR383)
Tanker	An oceangoing ship designed to haul liquid bulk cargo in world trade.
Tanker and Barge	Vessels that transport crude oil or petroleum products. Data are reported for movements between Petroleum and Administration for Defense (PAD) Districts; from a PAD District to the Panama Canal; or from the Panama Canal to a PAD District. (DOE5)
Tanker Man	Person trained, qualified, and certified to supervise transfer of liquid cargo (fuels) from shore to the barge. (TNDOT1)
Tare Weight	The weight of a container and/or packing materials without the weight of the goods it contains. (MARAD2)
Tariff	A published volume of rate schedules and general terms and conditions under which a product or service will be supplied. (DOE5)
Tarp	Tarpaulin cover for open top trailers. (ATA1)
Tattle Tale	(See also Squealer) Tachograph. (ATA1)
Taxi	The use of a taxicab by a driver for hire or by a passenger for fare. Also includes airport limousines. Does not include rental cars if they are privately operated and not picking up passengers in return for fare. (FHWA3)
Taxicabs	Establishments primarily engaged in furnishing passenger transportation by automobiles not operated on regular schedule or between fixed terminals. Taxicab fleet owners and organizations are included, regardless of whether drivers are hired or rent their cabs or are otherwise compensated. (BOC1)
Taxilane (TL)	The portion of the aircraft parking area used for access between taxiways and aircraft parking positions. (FAA12)
Taximeter	A mechanical or electrical device in a taxicab that records and indicates a charge or fare calculated according to distance traveled, waiting time, initial charge, number of passengers, and other charges authorized by ordinance or by rule. Some taximeters are part of electronic dispatching systems. (TRB1)
Taxiway (TW)	A defined path established for the taxing of aircraft from one part of an airport to another. (FAA12)
Taxiway Safety Area (TSA)	The surface alongside the taxiway prepared or suitable for reducing the risk of damage to an airplane unintentionally departing the taxiway. (FAA12)
Technical Factory Visit	A visit of officer in charge marine inspection (OCMI) personnel to a manufacturing facility to check for compliance with standards and regulations, examine products and answer technical questions. (USCG1)
Technology Transfer	Those activities that lead to the adoption of a new technique or product by users and involves dissemination, demonstration, training, and other activities that lead to eventual innovation. (23CFR420)
Telecommuting	Communicating electronically (by telephone, computer, fax, etc.) with an office, either from home or from another site, instead of traveling to it physically.
Temporary Living Quarters	A space in the interior of an automobile in which people may temporarily live and which includes sleeping surfaces, such as beds, and household conveniences, such as a sink, stove, refrigerator, or toilet. (49CFR523)
Terawatt Hour (TWH)	One trillion watt hours. (DOE5)
Terminal	Any location where freight either originates, terminates, or is handled in the transportation process; or commercial motor carriers maintain operating facilities. (23CFR658)
Terminal and Joint Terminal Maintenance For Motor Freight Transport Facility	Establishments primarily engaged in the operation of terminal facilities used by highway-type property carrying vehicles. Also included are terminals which provide maintenance and service for motor vehicles. (BOC1)
Terminal and Service For Motor Vehicle Passenger Transportation Facility	Establishments primarily engaged in the operation of motor vehicle passenger terminals and of maintenance and service facilities, not operated by companies that also furnish motor vehicle passenger transportation. (BOC1)
Terminal Area	A general term used to describe airspace in which approach control service or airport traffic control service is provided. (FAA2) (FAA8)
Terminal Area Facility	A facility providing air traffic control service for arriving and departing Instrument Flight Rule (IFR), Visual Flight Rule (VFR), Special Visual Flight Rules (VFR), Special Instrument Flight Rules (IFR) aircraft and, on occasion, en route aircraft. (FAA8)
Terminal Facility Activity	The sum of Total Airport Operations + Total Instrument Operations which equals Local Operations + Itinerant Operations + Primary Instrument Operations + Secondary Instrument Operations + Instrument Overflights. (FAA3)
Terminal Radar Approach Control (TRACON)	A Federal Aviation Administration (FAA) air traffic control facility using radar and air/ground communications to provide approach control services to aircraft arriving, departing, or transiting the airspace controlled by the facility. Service may be provided to both civil and military airports. (FAA10) (FAA13) (FAA14)
Terminal Storage	Service of providing warehouse or other terminal facilities for the storage of inbound or outbound cargo after the expiration of free time, including wharf storage, shipside storage, closed or covered storage, open or ground storage, bonded storage and refrigerated storage, after storage arrangements have been made. (MARAD1)
Terminated Carload	A carload which ends its journey and is unloaded on a particular railroad. (AAR1)
Terrace	A steplike feature between higher and lower ground; a relatively flat or gently inclined shelf of earth, backed and fronted by steep slopes or manmade retaining walls. (DOI4)
Territorial Highway System (THS)	The full name is Federal-aid Territorial Highway System. A system of arterial and collector highways, plus inter-island connectors that are established under 23 U.S.C. 215 by each territory (Guam, Northern Marianas Islands, Samoa, and the Virgin Islands). (FHWA2)
Test Procedures	Specifies the methods and equipment the Coast Guard uses in determining whether boats comply with applicable standards. (USCG1)
Texas	That part of the upper deck of a river steamboat abaft the stacks used for officers' quarters. (TNDOT1)
Thalweg	The deepest water at any point in the river. The longitudinal line of greatest continuous depth in the river channel. (TNDOT1)
Thanksgiving Rise	An annual event on the Ohio River when the river swells to a crest around Thanksgiving time. (TNDOT1)
Then On Down	Channel report term written as proceeding to a designated mile or designated bank, then on down to the end of another designated location, such as "fourth dike below this light." (TNDOT1)
Thermal Limit	The maximum amount of power a transmission line can carry without suffering heat-related deterioration of line equipment, particularly conductors. (DOE5)
Thermal Storage	Storing heat for use at a later time. For example, ceramic bricks can be charged up to 1,200 degrees Fahrenheit in an 8-hour period and the heat released over the next 16 hours. (DOE5)
Thermosiphon System	A solar collector system for water heating in which circulation of the collection fluid through the storage loop is provided solely by the temperature and density difference between the hot and cold fluids. (DOE5)
Third Party	(See also Accident) When referring to motor vehicle accidents; the Government being the first party and the government owned vehicle (GOV) operator being the second party, the third party is the other concern in an accident. (GSA2)
Third party Logistics (3PL)	Provider. A specialist in logistics who may provide a variety of transportation, warehousing, and logistics related services to buyers or sellers. These tasks were previously performed in house by the customer.
Third Rail	An electric conductor, located alongside the running rail, from which power is collected by means of a sliding shoe attached to the truck of electric rail cars or locomotives. (TRB1)
Third Structure Tax	Any tax on road users other than registration fees or fuel taxes. (ATA2)
Threshold (TH)	The beginning of that portion of the runway available for landing. When the threshold is located at a point other than at the beginning of the pavement, it is referred to as either a displaced or relocated threshold. (FAA12)
Through Bill of Lading	Bill of lading covering transportation through more than one mode in the chain of transport from shipper to consignee. (MARAD1)
Throughput	Total amount of freight imported or exported through a seaport measured in tons or TEUs.
Throughput Capacity	The estimated potential tonnage of cargo that can be processed and handled through a port terminal or berthing facility during a given time period, determined by the design specifications of the terminal. (MARAD1)
Throughput Charge	The charge for moving a container through a container yard off or onto a ship. (MARAD2)
Ticketing and Fare Collection	All activities associated with fare collection and counting activities including supervision and clerical support. Includes printing, distributing, selling and controlling of tickets, tokens and passes; pulling and transporting vaults to counting facilities; counting and auditing of fare collection; and, providing security for the fare collection process. (FTA1)
Tidal	Flat foreshore area that is submerged at high tide, exposed or a wash at low tide, and generally devoid of vegetation. (DOI3)
Tidal Gauge	An instrument for measuring the height of the tide. (DOI4)
Tidegate	(See also Gate, Floodgate) Gate with a free-swinging barrier that is placed near or at the outlet of a conduit flowing into a body of water subject to high water from tides in order to separate fresh from salt water. (DOI3)
Tie Line	A transmission line connecting two or more power systems. (DOE5)
Tie Off to Bank	To moor one or more barges to the bank of the river, utilizing trees or any other structure available for securing the mooring wires. (TNDOT1)
Tied Up	When roadway is obstructed. (ATA1)
Till	Channel report term meaning to steer toward a certain mark in a direct line until the occurrence or existence of another named fact taken place. (TNDOT1)
Till From	An old river phrase meaning that after steering past a set of marks, the mark that is on the stern now becomes "till." One should keep the past mark on the stern and lineup. (TNDOT1)
Tilt Cab	Vehicle designed with engine beneath cab and having provision for tilting the cab forward on a pivot near the front bumper to provide easy access to the engine. (TII1) (TII2)
Timberhead	One or two upright pins or steel bollards on the heads and stems of barges whereby the barges are coupled together for towing end to end. The term originated from the wooden timbers mounted on early wooden barges that were prevalent for transporting coal many years ago. (TNDOT1)
Time In Service	With respect to maintenance time records, means the time from the moment an aircraft leaves the surface of the earth until it touches it at the next point of landing. (14CFR1)
Time Locking	A method of locking, either mechanical or electrical, which, after a signal has been caused to display an aspect to proceed, prevents, until after the expiration of a predetermined time interval after such signal has been caused to display its most restrictive aspect, the operation of any interlocked or electrically locked switch, movable-point frog, or derail in the route governed by that signal, and which prevents an aspect to proceed from being displayed for any conflicting route. (49CFR236)
Time On Sortie	Total time on sortie from homeport/station or diversion from another mission until return to homeport/station or return for replenishment. (USCG3)
Time Release	A device used to prevent the operation of an operative unit until after the expiration of a predetermined time interval after the device has been actuated. (49CFR236)
Time Service Begins	Start of morning transit service, i.e., the time when a revenue service vehicle leaves the garage or point of dispatch. (FTA1)
Time Service Ends	End of night transit service, i.e., the time when a revenue service vehicle returns to the garage or point of dispatch. (FTA1)
Time Zone	A geographic region within which the same standard time is used. (DOI4)
Timed Transfer System	A transit network consisting of one or more nodes (transit centers) and routes or lines radiating from them. The system is designed so that transit vehicles on all or most of the routes or lines are scheduled to arrive at a transit center simultaneously and depart a few minutes later; thus transfers among all the routes and lines involve virtually no waiting. TTS is typically used in suburban areas and for night service; in other words, for those cases in which headways are long. (TRB1)
Timing Relay	A relay which will not close its front contacts or open its back contacts, or both, until the expiration of a definite time interval after the relay has been energized. (49CFR236)
Tip Fin	See Winglet.
Tipple	A central facility used in loading coal for transportation by rail or truck. (DOE5)
Tire Capacity	The rated capacity in pounds that the tire is designed to support, as established by the current Tire and Rim Association ratings. (GSA2)
Title VI	Title VI of the Civil Rights Act of 1964. Prohibits discrimination in any program receiving federal assistance.
To Halfway Between	Channel report term meaning to steer halfway between two separately designated reference objects. (TNDOT1)
Toll Road	Travel fee is collected at entry or exit. (DOI3)
Ton mile	A measure of output for freight transportation; reflects weight of shipment and the distance it is hauled; a multiplication of tons hauled by the distance traveled.
Ton Miles Tax	A tax calculated by measuring the weight of each truck for each trip. The gross weight is assigned a tax rate which is multiplied by the miles of travel. (ATA2)
Ton Offered Kilometer	Unit of measure representing the movement of one ton available in a freight vessel when performing the services for which it is primarily intended over one kilometer. (TNDOT1)
Ton-Deadweight	The carrying capacity of the ship in terms of the weight in tons of the cargo, fuel, provisions, and passengers which a vessel can carry. (TNDOT1)
Ton-Displacement	The weight of the volume of water which the fully loaded ship displaces. (TNDOT1)
Ton-Kilometer By Inland Waterways	Unit of measure of goods transport which represents the transport of one ton by inland waterways over one kilometer. (TNDOT1)
Ton-Mile (Water)	The movement of one ton of cargo the distance of one statute mile. Domestic ton-miles are calculated by multiplying tons moved by the number of statute miles moved on the water (e.g., 50 short tons moving 200 miles on a waterway would yield 10,000 ton-miles for that waterway). Ton-miles are not computed for ports. For coastwise traffic, the shortest route that safe navigation permits between the port of origin and destination is used to calculate ton-miles.
Tonne	See Metric Ton.
Ton-Registered	The cubical contents or burden of a vessel in tons of 100 cubic feet. The space within a vessel in units of 100 cubic feet. (TNDOT1)
Tooling Down the Highway	Driving vehicle along at normal speed. (ATA1)
Toothpick	Steel bar about 3 feet long placed in ratchet ends to keep wire from turning when tightening ratchet. (TNDOT1)
Top Around	The turning of a tow from upbound to downbound, either intentionally or unintentionally. (TNDOT1)
Top Plate	A metal plate secured to a locking bracket to prevent the cross locking from being forced out of the bracket. (49CFR236)
Top Shell	The tank car tank surface, excluding the head ends and bottom shell of the tank car tank. (49CFR171)
Torque	The amount of twisting effort exerted at the crankshaft by an engine. The unit of measure is a pound-foot which represents a force of one pound acting at right angles at the end of an arm one foot long. 1) gross torque the maximum torque developed by an engine without allowing for the power absorbed by accessory units; 2) net torque the torque available at the flywheel after the power required by engine accessories has been provided. (TII1) (TII2)
Torso Line	The line connecting the "H" point and the shoulder reference point as defined in Society of Automotive Engineers (SAE) Recommended Practice J787g, "Motor Vehicle Seat Belt Anchorage," September 1966. (49CFR571)
Total Aircraft Revenue Mile	The distance flown by aircraft in revenue passenger and/or nonpassenger service, including extra sections. (BTS5)
Total Benefit/Cost Ratio	The sum of five categories of quantifiable project benefits divided by the anualized cost of the project.
Total Departures Performed In All Services	The total number of aircraft takeoffs made in scheduled and nonscheduled service. (FAA15)
Total Departures Performed In Nonscheduled Services	The total number of aircraft takeoffs made in nonscheduled service. (FAA15)
Total Departures Performed In Scheduled Service	The total number of aircraft takeoffs made in scheduled service including extra sections. (FAA15)
Total Energy	All energy consumed by end-users, including electricity but excluding the energy consumed at electric utilities to generate electricity. (In estimating energy expenditures, there are no fuel-associated expenditures for hydroelectric power, geothermal energy, solar power, or wind energy, and the quantifiable expenditures for process fuel and intermediate products are excluded.) (DOE5)
Total Energy Consumption	The sum of fossil fuel consumption by the five sectors (residential, commercial, industrial, transportation, and electric utility) plus hydroelectric power, nuclear electric power, net imports of coal coke, and electricity generated for distribution from wood, waste, geothermal, wind, photovoltaic, and solar thermal energy. (DOE3) (DOE5)
Total Facility Activity	The sum of En Route Facility Activity + Terminal Facility Activity. (FAA3)
Total Flight Service	The sum of flight plans originated and pilot briefs multiplied by two, plus the number of aircraft contacted. No credit is allowed for airport advisories or radio contacts. (FAA13)
Total Miles on Active Vehicle During the Period	The total miles acumulated on all active vehicles in the group during the period. (FTA1)
Total Operations	All arrivals and departures performed by military, general aviation, commuter/air taxi, and air carrier aircraft. (FAA14)
Total Revenue Load Factor	The percent that revenue ton-miles (passenger and nonpassenger) are of available ton-miles in revenue services, representing the proportion of the overall capacity that is actually sold and utilized. (BTS5)
Total Ton-Miles	The aircraft miles flown on each inter-airport hop multiplied by the tons of revenue traffic (passenger and nonpassenger) carrier on that hop. (BTS6)
Tour Operators	Establishments primarily engaged in arranging and assembling tours for sale through travel agents. Tour operators primarily engaged in selling their own tours directly to travelers are also included in this industry. (BOC1)
Tow	One or more barges or other floating vessels in the charge of a self-propelled vessel which has undertaken to transport such responsibility elsewhere. A tow is made-up when it has been hitched together and made ready for moving. A barge moored to the front of a towing vessel is the towbarge and the ones out in front are the lead barges. When a barge is towed alongside a towboat, it is "slung under her arm" or on the hip". When pulled behind, the barges are said to be "railroaded." When loosely coupled behind, it is called the "mule train." (TNDOT1)
Tow Line	A holding up line; normally a lashing from the forward head of one barge to the after head of a barge alongside. (TNDOT1)
Towboat	(See also Boat, Motorboat, Tug) A self-propelled, compact, shallow-draft boat with a squared bow and towing "knees" for pushing tows of barges on inland waterways. In early river transportation, the freight-carrying vessels were pulled or "towed." The contemporary method is to push barges but the traditional term "towboat" is still used for the modern barge pushers instead of the more accurate term "pushboat". (TNDOT1)
Tower	A tall framework or structure, the elevation of which is functional. (DOI4)
Towhead	A small island or spit of land extending above or below the main or larger island. It may or may not be recently formed. (TNDOT1)
Towing	Engaged in towing any vessel or object, other than a person. (USCG2)
Towing and Tugboat Service	Establishments primarily engaged in furnishing marine towing and tugboat services in the performance of auxiliary or terminal services in harbor areas. The vessels used in performing these services do not carry cargo or passengers. (BOC1)
Towing Knees	The heavily constructed steel angles mounted in a fixed position on the bow of all western river towboats to enable them to push against the stern of barges. (TNDOT1)
Track	A pair of rails over which railway vehicles can run. (UN1)
Track Circuit	An electrical circuit of which the rails of the track form a part. (49CFR236)
Track Damage	All costs, including labor and material, associated with the repair or replacement in kind of signals, track, track structures (including bridges or tunnels) or roadbeds that were damaged in a collision, derailment or other reportable event. When track, signals, structures, etc. are damaged beyond repair, the current cost of new materials is to be used. However, replacement of second-hand rail with second-hand rail, may be charged at the current cost of such rail. (FRA2)
Track Mile	(See also Miles of Track Operated) One mile of single track. (AAR1)
Trackage Rights Agreement	An agreement through which a railroad obtains access and provides service over tracks owned by another railroad where the owning railroad retains the responsibility for operating and maintaining the tracks. (49CFR245)
Tracked Air Cushion Vehicle	A laterally guided vehicle that is suspended above the track by an air cushion system. (TRB1)
Tracked Levitated Vehicle	A laterally guided vehicle that is suspended above the track by magnetic levitation. (TRB1)
Trackless Trolley	Another name for "trolleybus." (APTA1)
Tractor	A vehicle designed for pulling loads greater than the weight actually applied to the vehicle. The trailer on which the load is carried is connected to the tractor via the fifth wheel. (TII1) (TII2)
Tractor (or Truck Tractor)	The noncargo carrying power unit that operates in combination with a semitrailer or trailer, except that a truck tractor and semitrailer engaged in the transportation of automobiles may transport motor vehicles on part of the power unit. (23CFR658)
Tractor-Semitrailer	A combination vehicle consisting of a power unit (tractor) and a semitrailer. (ATA2)
Traffic Accident	An accident that involved a motor vehicle that occurred on a public highway or road in the United States and that resulted in property damage or personal injury. Does not include accidents that happened in a parking lot, in a driveway, on a private road, or in a foreign country. (FHWA3)
Traffic Alert and Collision Avoidance, Type I System (TCAS)	Utilizes interrogations of, and replies from, airborne radar beacon transponders and provides traffic advisories to the pilot. (14CFR1)
Traffic Alert and Collision Avoidance, Type II System (TCAS)	Utilizes interrogations of, and replies from airborne radar beacon transponders and provides traffic advisories and resolution advisories in the vertical plane. (14CFR1)
Traffic Alert and Collision Avoidance, Type III System (TCAS)	Utilizes interrogation of, and replies from, airborne radar beacon transponders and provides traffic advisories and resolution advisories in the vertical and horizontal planes to the pilot. (14CFR1)
Traffic Assignment Zone	In planning, a division of a study area that is represented by a centroid and used for traffic assignment purposes. (TRB1)
Traffic Circle	A junction of roads that form a circle around which traffic normally moves in one direction. (DOI3)
Traffic Control Device	A sign, signal, marking, or other device placed on or adjacent to a street or highway, by authority of a public body or official that has jurisdiction, to regulate, warn, or guide traffic. (TRB1)
Traffic Control System	A block signal system under which train movements are authorized by block signals whose indications supersede the superiority of trains for both opposing and following movements on the same track. (49CFR236)
Traffic Count	A record of the number of vehicles, people aboard vehicles, or both, that pass a given checkpoint during a given time period. (TRB1)
Traffic Flow Management	The process that ensures optimum flow of air traffic to and through areas during times when demand exceeds, or is expected to exceed, the available capacity of the system; an element of the air traffic management process. (FAA7)
Traffic Inspection Facility	An area having facilities to examine pedestrian and vehicular traffic and/or cargo. (DOI3)
Traffic Known	With respect to Air Traffic Control (ATC) clearances, means aircraft whose altitude, position, and intentions are known to ATC. (FAA4)
Traffic Locking	Electric locking which prevents the manipulation of levers or other devices for changing the direction of traffic on a section of track while that section is occupied or while a signal displays an aspect for a movement to proceed into that section. (49CFR236)
Traffic Management Coordinator	A traffic management specialist resident at the Air Route Traffic Control Center (ARTCC) Traffic Management Unit (TMU) providing coordination between the national level central flow control function of the ATCCC and local (ARTCC) controllers. (FAA8)
Traffic Management Specialist	Specialist resident at the Air Traffic Control Command Center (ATCCC) who coordinates between local traffic management specialists at ARTCCs and manages flow control operations. (FAA8)
Traffic Management Unit (TMU)	A non-control, coordination position at the Air Route Traffic Control Center (ARTCC) connected to the central flow control function at the ATCCC and responsible for dissemination of flow control information at the local level. (FAA8)
Traffic Pattern	The traffic flow that is prescribed for aircraft landing at, taxiing on, or taking off from, an airport. (14CFR1)
Traffic Separation Scheme	Area of water with lanes designated to separate opposing streams of vessel traffic. (DOI4)
Traffic Violation	See Serious Traffic Violation.
Trafficway	That part of a trafficway designed, improved, and ordinarily used for motor vehicle travel. (NHTSA3)
Trafficway (Highway)	Any right-of-way open to the public as a matter of right or custom for moving persons or property from one place to another, including the entire width between property lines or other boundaries.
Trafficway Class	A classification of highways based on a route sign. (NHTSA1)
Trail	A cleared path, beaten track, or improved surface, as through woods or wilderness, not usually trafficked by vehicles because of width, seasonal conditions, or access restrictions. (DOI3)
Trail Dike	A dike of wooden pile construction or rock that extends usually from the riverbank outward toward the channel and trails downstream so as to direct the flow of water into the channel. Trail dikes help maintain the channel by keeping it swept by the directional currents. (TNDOT1)
Trailer	A motor vehicle with or without motive power, designed for carrying persons or property and for being drawn by another motor vehicle. (49CFR571) (ATA2)
Trailer Converter Dolly	A trailer chassis equipped with one or more axles, a lower half of a fifth wheel and a drawbar. (49CFR571)
Trailer On a Flat Car/Container On a Flat Car (TOFC/COFC)	(See also Intermodal) Often referred to as intermodal service. (AAR1)
Trailer on Flatcar (TOFC)	Transport of trailers with their loads on specially designed rail cars.
Trailer-On-Flatcar (TOFC)	(See also Intermodal) Transportation of containers on the chassis of railroad flatcars. (MARAD1)
Trailership	A vessel, other than a carfloat, specifically equipped to carry motor transport vehicles and fitted with installed securing devices to tie down each vehicle. The term trailership includes Roll-on/Roll-off (RO/ RO) vessels. (49CFR171)
Trailing Movement	The movement of a train over the points of a switch which face in the direction in which the train is moving. (49CFR236)
Trailing Point Switch	A switch, the points of which face away from traffic approaching in the direction for which the track is signaled. (49CFR236)
Train	A locomotive unit or locomotive units coupled, with or without cars and with or without markers displayed. Included in this definition are those trains consisting entirely of self-propelled units designed to carry passengers and/or freight traffic. (FRA2) (FRA4)
Train Accident	Any collision, derailment, fire, explosion, act of God, or other event involving the operation of on-track equipment and resulting in reportable damage to track or on-track equipment above an established dollar threshold. (FRA2) (FRA4)
Train Berth	In rail operations, the space designated for a train of given length to occupy when it is stopped at a station platform, in a terminal, on a transfer track, or at some other designated place. (TRB1)
Train Density	1) The number of trains that can be operated safely over a segment of railroad in each direction during a 24-hr. period. 2) The average number of trains that pass over a specified section of railroad in a specified period. (TRB1)
Train Hour	The elapsed time of a road freight train between the time of leaving the initial terminal and the time of arrival at the final terminal, including train switching at the time of arrival at the final terminal, including train switching at way stations and delays on road. (AAR1)
Train Incident	Any event involving the movement of railroad on-track equipment that results in a death, a reportable injury, or a reportable illness, but in which railroad property damage does not exceed the reporting threshold. (FRA3) (FRA4)
Train Line Mileage	The aggregate length of all line-haul railroads. It does not include the mileage of yard tracks or sidings, nor does it reflect the fact that a mile of railroad may include two or more parallel tracks. Jointly-used track is counted only once.
Train Mile	The movement of a train a distance of one mile measured by the distance between terminals and/or stations and includes yard switching miles, train switching miles, and work train miles, Yard switching miles may be computed on any reasonable, supportable, and verifiable basis. In the event actual mileage is not computable by other means, yard switching miles may be computed at the rate of 6 mph for the time actually engaged in yard switching service. (49CFR245)
Train or Yard Crew	One or more railroad employees assigned a controlling locomotive, under the charge and control of one crew member; called to perform service covered by Section 2 of the Hours of Service Act; involved with the train or yard movement of railroad rolling equipment they are to work with as an operating crew; reporting and working together as a unit that remains in close contact if more than one employee; and subject to the railroad operating rules and program of operational tests and inspections required in 49 CFR 217.9 and 217.11. (49CFR218)
Train order	Mandatory directives issued as authority for the conduct of a railroad operation outside of yard limits. (49CFR221)
Training (Instructional)	Any use of an aircraft for the purpose of formal instruction with the flying instructor aboard, or with the maneuvers on the particular flight, specified by the flight instructor; excludes proficiency flying. (FAA10)
Trainmen	Persons employed as engineers and motormen, firemen and helpers, conductors, brakemen and flagmen engaged in passenger, freight, yard or work service and train baggagemen. Prior to 1984 this category did not include hostlers. The Interstate Commerce Commission revised the occupational groupings in 1984 and now includes hostlers in the train and engine category. (FRA3)
Train-Mile	The movement of a train, which can consist of many cars, the distance of one mile. A train-mile differs from a vehicle-mile, which is the movement of one car (vehicle) the distance of one mile. A 10-car (vehicle) train traveling 1 mile is measured as 1 train-mile and 10 vehicle-miles. Caution should be used when comparing train-miles to vehicle-miles.
Trainship	A vessel other than a rail car ferry or carfloat, specially equipped to transport railroad vehicles, and fitted with installed securing devices to tie down each vehicle. (49CFR171)
Tramp	An oceangoing vessel that does not operate along a definite route or on a fixed schedule, but rather calls at any port where cargo is available. (TNDOT1)
Tramp Line	An ocean carrier company operating tramp steamers not on regular runs or schedules. (MARAD2)
Tramway	Another name for "light rail." (APTA1)
Transfer Capability	The overall capacity of interregional or international power lines, together with the associated electrical system facilities, to transfer power and energy from one electrical system to another. (DOE5)
Transfer Center	A fixed location where passengers interchange from one route or vehicle to another. (APTA1)
Transfer Charge	An extra fee charged for a transfer to use when boarding another transit vehicle to continue a trip. (APTA1)
Transfer of Control	The action whereby control responsibility for an aircraft is transferred from one controller to another. (FAA8)
Transfer Piping	A system of permanent and temporary piping used for transferring hazardous fluids between any of the following liquefaction process facilities, storage tanks, vaporizers, compressors, cargo transfer systems, and facilities other than pipeline facilities. (49CFR193)
Transfer System	Includes transfer piping and cargo transfer system. (49CFR193)
Transferring Controller/Facility	A controller/facility transferring control of an aircraft to another controller/facility. (FAA8)
Transformer	An electrical device for changing the voltage of alternating current. (DOE5)
Transit	Another name for "public transportation." (APTA1)
Transit Bus	(See also Intercity Bus, Motor Bus, Motorbus, School and Other Nonrevenue Bus) A bus designed for frequent stop service with front and center doors, normally with a rear-mounted diesel engine, low-back seating, and without luggage storage compartments or rest room facilities. Includes motor bus and trolley coach. (APTA1) (DOE6)
Transit Mall	A type of exclusive right-of-way reserved for transit vehicles in revenue service and pedestrian traffic. (FTA1)
Transit Mode	(See also Rail Mode, Rapid Rail, Rapid Transit Rail, Transit Railroad, Transit Railway) Generally defined as urban and rural public transportation services including commuter trains, ferry service, heavy rail (rapid rail) and light rail (streetcar) transit systems, and local transit buses and taxis. (BTS1)
Transit of An Inland Waterways Transport (IWT) Vessel	Any laden or unladen IWT vessel which has entered and left the country at different points by whatever means of transport provided the total journey within the country was by inland waterway and that there has been no loading or unloading operation in the country. (TNDOT1)
Transit Property	All facilities which are directly controlled by a transit agency (agency is responsible for cleaning or maintaining) or provided to a transit agency for its use by another public or private entity (formal/informal agreement with the owner wherein services or facilities are provided to benefit the transit agency). This includes stations, exclusive right-of-ways, bus stops, and maintenance facilities. (FTA1)
Transit Property Damage	Any damage to transit property that requires the repair or replacement of transit agency vehicles or facilities (track, signals, buildings) to a state equivalent to that which existed prior to the incident. (FTA1)
Transit Railroad	(See also Rail Mode, Rapid Rail, Rapid Transit Rail, Transit Mode, Transit Railway) Includes heavy and light transit rail. Heavy transit rail is characterized by exclusive rights-of-way, multi-car trains, high speed rapid acceleration, sophisticated signaling, and high platform loading. Also known as subway, elevated railway, or metropolitan railway (metro). Light transit rail may be on exclusive or shared rights-of-way, high or low platform loading, multi-car trains or single cars, automated or manually operated. In generic usage, light rail includes streetcars, trolley cars, and tramways. (DOE6)
Transit Railway	(See also Rail Mode, Rapid Rail, Rapid Transit Rail, Transit Mode, Transit Railroad) Suburban and urban railway (including light rail such as trolleys, cable cars and car lines) used only for transporting people. (DOI3)
Transit System	An organization (public or private) providing local or regional multi-occupancy-vehicle passenger service. Organizations that provide service under contract to another agency are generally not counted as separate systems. (APTA1)
Transit Trip	A one-way trip by a transit vehicle in revenue service starting at one terminal point of a route and ending at another terminal point. A round trip is counted as two separate trips. In the case where the route is a pure loop involving entirely different streets and pick-up points, and where there is no logical way to identify the terminal points, then traversing of the loop can be regarded as a single trip. (FTA1)
Transit Vehicle	Includes light, heavy, and commuter rail; motorbus; trolley bus; van pools; automated guideway; and demand responsive vehicles.
Transit Zones	A form of free trade zone. They are ports of entry in coastal countries that are established as storage and distribution centers for the convenience of a neighboring country lacking adequate port facilities or access to the sea. A transit zone is administered so that goods in transit to or from the neighboring country are not subject to the customs duties, import controls or many of the entry and exit formalities of the host country. (USTTA1)
Transitway	Another name for "High-Occupancy Vehicle Lane." (APTA1)
Transloading	Transferring bulk shipments from the vehicle/ container of one mode to that of another at a terminal interchange point.
Transmission Gas Company	A company which obtains at least 90 percent of its gas operating revenues from sales for resale and/or transportation of gas for others and/or main line sales to industrial customers and classifies at least 90 percent of mains (other than service pipe) as field and gathering, storage and/or transmission. (AGA1)
Transmission Network	A system of transmission or distribution lines so cross-connected and operated as to permit multiple power supply to any principal point. (DOE5)
Transmission Pipeline	Pipelines (mains) installed for the purpose of transmitting gas from a source or sources of supply to one or more distribution centers, or to one or more large-volume customers, or a pipeline installed to interconnect sources of supply. In typical cases, transmission lines differ from gas mains in that they operate at higher pressures, are longer, and the distance between connections is greater. (AGA1)
Transmission Type	The transmission is the part of a vehicle that transmits motive force from the engine to the wheels, usually by means of gears for different speeds using either a hydraulic "torque-converter" (automatic) or clutch assembly (manual). On front-wheel drive cars, the transmission is often called a "transaxle". Fuel efficiency is usually higher with manual rather than automatic transmissions, although modern, computer-controlled automatic transmissions can be efficient. (DOE4) (DOE5)
Transmission Types	A3-Automatic three speed, A4-Automatic four speed, A5-Automatic five speed, L4-Automatic lockup four speed, M5-Manual five speed. (DOE6)
Transponder	A piece of equipment which, when set upon a specific radio frequency, emits a directional signal of its own and enables the receiver to track or monitor the truck's location. (BOC3)
Transport	Movement of natural, synthetic, and/or supplemental gas between points beyond the immediate vicinity of the field or plant from which produced except 1) For movements through well or field lines to a central point for delivery to a pipeline or processing plant within the same state or 2) Movements from a citygate point of receipt to consumers through distribution mains. (DOE5)
Transport Airport	An airport designed, constructed and maintained to serve airplanes in Aircraft Approach Category C and D. (FAA12)
Transport Related Expenses	All expense items applicable to the generation of transport-related revenues. (BTS4)
Transport Revenue	Revenues from the transportation by air of all classes of traffic in scheduled and nonscheduled services. (BTS4)
Transport Vehicle	A cargo-carrying vehicle such as an automobile, van, tractor, truck, semitrailer, tank car or rail car used for the transportation of cargo by any mode. Each cargo carrying body (trailer, rail car, etc.) is a separate transport vehicle. (49CFR171)
Transportation	See also Transport, Travel, Trip.
Transportation Administration and Support	All activities associated with transportation administration, revenue vehicle movement control and scheduling including supervision and clerical support. (FTA1)
Transportation Agreement	Any contractual agreement for the transportation of natural and/or supplemental gas between points for a fee. (DOE5)
Transportation Bill	The bill refers to the market value of all purchases of transportation services and facilities; it includes all domestic expenditures made by an economy for transportation purposes. Although the transportation bill does not reflect several significant non-market costs, it is a useful indicator of a country's transportation expenditures, and transportation analysts closely follow changes in the bill and its components. (BTS1)
Transportation Brokerage	1) Coordination of transportation services in a defined area. The transportation broker may centralize vehicle dispatch, record keeping, vehicle maintenance, and other functions under contractual arrangement with agencies, municipalities, and other organizations. 2) A method of matching travelers with a variety of transportation providers through use of central dispatching and administrative facilities. (TRB1)
Transportation Conformity	Process to assess the compliance of any transportation plan, program, or project with air quality implementation plans. The conformity process is defined by the Clean Air Act.
Transportation Control Measures (TCM)	Transportation strategies that affect traffic patterns or reduce vehicle use to reduce air pollutant emissions. These may include HOV lanes, provision of bicycle facilities, ridesharing, telecommuting, etc. Such actions may be included in a SIP if needed to demonstrate attainment of the NAAQS.
Transportation Demand Management (TDM)	Programs designed to reduce demand for transportation through various means, such as the use of transit and of alternative work hours.
Transportation Enhancement Activities (TE)	Provides funds to the States for safe bicycle and pedestrian facilities, scenic routes, beautification, restoring historic buildings, renovating streetscapes, or providing transportation museums and visitors centers. 23 U.S.C. 101(a) and 133(b)(8).
Transportation Equity Act for the 21st Century (TEA-21)	Authorized in 1998, TEA-21 authorized federal funding for transportation investment for fiscal years 1998-2003. Approximately $217 billion in funding was authorized, which was used for highway, transit, and other surface transportation programs.
Transportation Improvement Program (TIP)	A document prepared by a metropolitan planning organization that lists projects to be funded with FHWA/FTA funds for the next one- to three-year period.
Transportation Industry	Those establishments or parts of establishments that build transportation facilities and equipment; operate transportation facilities; provide for-hire transportation services for individuals, households, businesses, or government agencies; provide supporting in-house transportation for a business or government agency; arrange transportation services for individuals, households, businesses or government agencies; provide supporting services necessary to the provision of transportation services; or administer transportation programs. This definition includes a diverse cross section of the economy, such as automobile manufacturers, railroads, travel agents, school district bus operators, port authorities, gas stations, and the trucking fleets of major grocery chains. (BTS2)
Transportation Infrastructure	A federal credit program under which the USDOT may provide three forms of credit assistance - secured (direct) loans, loan guarantees, and standby lines of credit - for surface transportation projects of national or regional significance. The fundamental goal is to leverage federal funds by attracting substantial private and non-federal co-investment in critical improvements to the nation's surface transportation system.
Transportation Interface and Reporting System (TIRES)	Processes all income earned and expenses incurred in operating the Interagency Fleet Management System. TIRES produces profit and loss reports as well as other detail reports for output to FSS. Sales transactions are generated for input into the Automotive Billing (AUTOBILL) module. (GSA2)
Transportation Management Area (TMA)	1) All urbanized areas over 200,000 in population, and any other area that requests such designation. 2) An urbanized area with a population over 200,000 (as determined by the latest decennial census) or other area when TMA designation is requested by the Governor and the MPO (or affect local officials), and officially designated by the Administrators of the FHWA and the FTA. The TMA designation applies to the entire metropolitan planning area(s). (23CFR500)
Transportation Research Information Services (TRIS)	The Transportation Research Board-maintained computerized storage and retrieval system for abstracts of ongoing and completed research, development, and technology transfer (RD&T) activities, including abstracts of RD&T reports and articles. (23CFR420)
Transportation Sector	Consists of both private and public passenger and freight transportation, as well as government transportation, including military operations. (DOE6)
Transporter	The party or parties, other than buyer or seller, owning the facilities by which gas or liquefied natural gas (LNG) is physically transferred between buyer and seller. (DOE5)
Transshipment	The transfer of goods from one carrier to another. (TNDOT1)
Transshipments	Shipments that enter or exit the United States by way of a U.S. Customs port on the northern or southern border, but whose origin or destination is a country other than Canada or Mexico.
Trap Circuit	A term applied to a circuit used where it is desirable to provide a track circuit but where it is impracticable to maintain a track circuit. (49CFR236)
Travel	See also Transport, Transportation, Trip.
Travel Advisory Program	The Department of State manages a travel advisory program which publicizes 1) Travel warnings which are issued when State decides to recommend that Americans avoid travel to a certain country and 2) Consular information sheets, issued for every country, which advise travelers of health concerns, immigration and currency regulations, crime and security conditions, areas of unrest or instability, and the location of U.S. embassies or consulates. (USTTA1)
Travel Agencies	Establishments primarily engaged in furnishing travel information and acting as agents in arranging tours, transportation, rental of cars, and lodging for travelers. (BOC1)
Travel Day	A 24-hour period from 4:00 a.m. to 3:59 a.m. designated as the reference period for studying trips and travel by members of a sampled household. (FHWA3)
Travel Day Trip	A travel day trip is defined as any one-way travel from one address (place) to another by any means of transportation (e.g., private motor vehicle, public transportation, bicycle, or walking). When travel is to more than one destination, a separate trip exists each time one or both of the following criteria is satisfied the travel time between two destinations exceeds 5 minutes, and/or the purpose for travel to one destination is different from the purpose for travel to another. The one exception is travel within a shopping center or mall. It is to be considered travel to one destination, regardless of the number of stores visited. (FHWA3)
Travel Density	The average number of vehicle miles driven on a section of highway each day divided by the length of the section in miles. It is expressed as a number of vehicles and may be referred to as average daily traffic (ADT). (FHWA1)
Travel Model Improvement Program (TMIP)	TMIP supports and empowers planning agencies through leadership, innovation and support of planning analysis improvements to provide better information to support transportation and planning decisions.
Travel Period	The 13 days immediately preceding the travel day and the designated travel day for a sampled household, for a total of 14 days. (FHWA3)
Travel Period Trip	A travel period trip is one-way to a destination which is 75 miles or more from home with a return home trip during the 14-day travel period. Travel to the destination is counted as one trip and travel to return home is counted as another trip. For example, a person living in Denver flies to San Francisco, stays one week, and returns to Denver during the 14-day travel period. This would be counted as two travel period trips-one outgoing and one return. The only time a travel period trip would not have a return trip collected is when the respondent moves his/her residence. (FHWA3)
Travel Surface	The type of material which forms the travel surface. Codes as follows AG-aggregate, B-bituminous, C-concrete, CA-caliche, N-natural (graded and drained), NU- natural unimproved (wheel tracks, O.R.V.). (DOI2)
Traveler	A person who stays for a period of less than 1 year in a country of which he or she is not a resident. Military and other government personnel and their dependents stationed outside their country of residence are not considered travelers, regardless of the length of their stay abroad; they are considered to have remained within the economy of their home country. The definition of travelers also excludes owners or employees of business enterprises who temporarily work abroad in order to further the enterprise's business, but intend to return to their country of residence within a reasonable period of time. (USTTA1)
Tread	Distance between the centers of tires at the points where they contact the road surface. Duals are measured from the center of dual wheels. (TII1) (TII2)
Treasury Stock	The cost of reacquired capital stock issued by the air carrier and not retired or cancelled. (BTS4)
Trespasser	Any person whose presence on railroad property, used in railroad operation, is prohibited or unlawful. (FRA3)
Trespasser (Rail)	Any person whose presence on railroad property used in railroad operations is prohibited, forbidden, or unlawful.
Trespassers (Class E)	Persons who are on that part of railroad property used in railroad operation and whose presence is prohibited, forbidden, or unlawful. (FRA2)
Triaxle	Three axle tractor or trailer. (ATA1)
Tribal Control Schedule	The implementing document for the Tribal TIP. The ITG may elect to develop the tribal control schedule under Self-Governance compact or Indian Self-Determination contract. The tribal control schedule is an accounting and project management tool that is developed from the tribal TIP. It contains detailed project and tasks information for all projects identified in the tribal TIP. Project information is included in the areawide control schedule without changing the total dollar amounts.
Tribal Lands	Land held in trust for Indian people, restricted Indian land which is not subject to fee title alienation without the approval of the Federal Government, and fee lands owned by tribal governments.
Tribal Priority List	A list of transportation projects which the ITG considers a high priority.
Tribal Technical Assistance Program Center (TTAP)	These centers are responsible for providing transportation assistance to native Americans that includes, but is not limited to, circuit rider programs, providing training on intergovernmental transportation planning and project selection, and tourism recreation travel.
Tribal TIP	A multi-year, financially constrained, list of proposed transportation projects to be implemented within or providing access to Indian country during the next 3-5 years. It is developed from the tribal priority list.
Trip	A movement of a locomotive over all or any portion of automatic train stop, train control or cab signal territory between the terminals for that locomotive; a movement in one direction. (49CFR236)
Trip Assignment	In planning, a process by which trips, described by mode, purpose, origin, destination, and time of day, are allocated among the paths or routes in a network by one of a number of models. (TRB1)
Trip Distribution	In planning, the process of estimating movement of trips between zones by using surveys or models. (TRB1)
Trip Generation	In planning, the determination or prediction of the number of trips produced by and attracted to each zone. (TRB1)
Trip Pilot	A pilot hired for one trip only. (TNDOT1)
Trip Type	"Intercity" or "city." Trip type is often subdivided into "charter" or "scheduled" service. (FHWA2)
Triple Truck	A truck-tractor which pulls 3 trailers. (BOC3)
Trolley Bus	Rubber-tired electric transit vehicle, manually steered and propelled by a motor drawing current, normally through overhead wires, from a central power source.
Trolley Car	Another name for "light rail." (APTA1)
Trolley Coach	Rubber-tired electric transit vehicle, manually-steered, propelled by a motor drawing current, normally through overhead wires, from a central power source not on board the vehicle. (DOE6)
Trolley Replica	A type of vehicle having the appearance of a trolley or streetcar but has rubber tires and is powered by a diesel, gasoline, propane or alternative fuel engine contained within the vehicle. Trolley replicas are classified as motor bus mode in the NTD system. (FTA1)
Trolleybus	Rubber-tired passenger vehicles operating singly on city streets. Trolleybuses are driven electrically with the power being drawn from an overhead electric line via trolleys. (FTA1)
Trolly Brake	A hand valve used to operate the trailer brakes independently of tractor brakes. (ATA1)
Truck	A motor vehicle designed to carry an entire load. It may consist of a chassis and body; a chassis, cab and body; or it may be of integral construction so that the body and chassis form a single unit. (ATA2)
Truck Crash	(See also Accident, Crash, Collision, Incident) A motor vehicle crash in which at least one medium or heavy truck is involved. (NHTSA4)
Truck Inventory and Use Survey	Survey designed to collect data on the characteristics and operational use of the nation's truck population. It is conducted every five years by the U.S. Bureau of the Census. Surveys were conducted in 1963, 1967, 1972, 1977, 1982, 1987 and 1992. (DOE6)
Truck Jockey	Truck driver. (ATA1)
Truck Size Classification	U.S. Bureau of the Census has categorized trucks by gross vehicle weight (GVW) as follows 1) Light-Less than 10,000 pounds GVW 2) Medium-10,001 to 20,000 pounds GVW 3) Light-heavy-20,001 to 26,000 pounds GVW 4) Heavy-heavy-26,001 pounds GVW or more. (DOE6)
Truck Tractor	A truck or self-propelled motor vehicle designed and/or used primarily for drawing other motor vehicles and not so constructed as to carry a load other than a part of the weight of the vehicle and the load so drawn. (49CFR390) (49CFR571)
Trucking	See also Semi, Semitrailer, Tractor, Tractor-Semitrailer, Truck.
Trucking (Except Local)	Establishments primarily engaged in furnishing "over-the-road" trucking services or trucking services and storage services, including household goods either as common carriers or under special or individual contracts or agreements, for freight generally weighing more than 100 pounds. Such operations are principally outside a single municipality, outside one group of contiguous municipalities, or outside a single municipality and its suburban areas. (BOC1)
Truckload (TL)	Quantity of freight required to fill a truck, or at a minimum, the amount required to qualify for a truckload rate.
Truck-Tractor Semitrailer-Semitrailer	The two trailing units are connected with a "B-train" assembly. The B-train assembly is a rigid frame extension attached to the rear frame of a first semitrailer which allows for a fifth wheel connection point for the second semitrailer. This combination has one less articulation point than the conventional "A dolly" connected truck-tractor semitrailer-semitrailer combination. (23CFR658)
Truck-Trailer Boat Transporter	A boat transporter combination consisting of a straight truck towing a trailer using typically a ball and socket connection. The trailer axle(s) is located substantially at the trailer center of gravity (rather than the rear of the trailer) but so as to maintain a downward force on the trailer tongue. (23CFR658)
True Airspeed	The airspeed of an aircraft relative to undisturbed air. True airspeed is equal to equivalent airspeed multiplied by (pO/p)l/2. (14CFR1)
Trunking	A casing used to protect electrical conductors. (49CFR236)
Trunnion	A cylindrical projection supporting a revolving part. (49CFR236)
Trust Fund	A fund credited with receipts that are held in trust by the government and earmarked by law for use in carrying out specific purposes and programs in accordance with an agreement or a statute.
Trust Funds	Accounts that are designated by law to carry out specific purposes and programs. Trust Funds are usually financed with earmarked tax collections.
Tug	A small but powerful vessel designed for moving larger vessels or for towing barges. Also called "towboat" or "pushboat". (TNDOT1)
Tug and Barge Combinations	The assessment of tolls requires tugs and barges in common transit to be considered as one unit. In this report the number of transits shown under this category represents the number of combined passages plus the number of individual tugs transiting the Seaway. (SLSDC1)
Tug Boat	A powered vessel designed for towing or pushing ships, dumb barges, pushed-towed barges, and rafts, but not for the carriage of goods.
Tunnel	1) An enclosed passageway, as for trains, automobiles, and so on, through or under an obstruction, such as a city, mountain, river, or harbor. 2) An underground passage. (TRB1)
Tunnel Entrance	Opening that affords entry to an underground or underwater passage. (DOI3)
Turn a Tow	To exchange tows, as when a towboat meets another towboat belonging to the same company proceeding in the opposite direction and they exchange their entire tows and return in the same direction from whence they came. (TNDOT1)
Turn Around	A truck that leaves from and returns to the same terminal. (ATA1)
Turn Signals	Lamps used to indicate a change in direction by emitting a flashing light on the side of a motor vehicle towards which a turn will be made. (49CFR393)
Turner-Fairbank Highway Research Center (TFHRC)	TFHRC provides FHWA and the world highway community with the most advanced research and development related to new highway technologies. The research focuses on providing solutions to complex technical problems through the development of more economical, environmentally sensitive designs; more efficient, quality controlled constructions practices; and more durable materials. The end result is a safer, more reliable highway transportation system.
Turning Basin	An area of water or enlargement of a channel used for the turning around of vessels. (TNDOT1)
Turning Roadway	A connecting roadway between two intersection legs that are at the same grade. (DOI3)
Turning Shipping Lane	Area designated as a place for ships to turn. (DOI3)
Turnout	1) In rail transportation, the assembly of a switch and a frog with closure rails by which rolling stock or trains can travel from a track onto either one of two diverging tracks; also known as a track switch. 2) A short side track or passage that enables trains, automobiles, and similar vehicles to pass one another. 3) A short passing lane on a highway. (TRB1)
Turnpike Double	A combination vehicle consisting of a tractor and two trailers of 45 to 48 feet. (ATA2)
Turntable	A circular, horizontal, rotating platform equipped with a railway track, used for turning locomotives, as in a roundhouse. (DOI3) (DOI4)
Twenty foot Equivalent Unit (TEU)	The 8 foot by 8 foot by 20 foot intermodal container is used as a basic measure in many statistics and is the standard measure used for containerized cargo.
Twin Screw	A truck or tractor with two rear axles, both driven by the engine. (ATA1)
Twin Trailer	A short semitrailer (under 29 feet) designed to be operated as part of a combination vehicle with a tandem trailer of similar length. (ATA2)
Two Axle Four Tire Truck	A motor vehicle consisting primarily of a single motorized device with two axles and four tires. (DOE6)
Two-Speed Axle	A rear axle with two ratios and a mechanism for selecting one or the other ratio, usually available with a standard type transmission. A double reduction axle which does not have a mechanism for selecting ratios is not a 2-speed axle. (TII1) (TII2)
Type	1) As used with respect to the certification, ratings, privileges, and limitations of airmen, means a specific make and basic model of aircraft, including modifications thereto that do not change its handling or flight characteristics. Examples include DC-7, 1049, and F-27; and 2) As used with respect to the certification of aircraft, means those aircraft which are similar in design. Examples include DC-7 and DC-7C; 1049G and 1049H; and F-27 and F27F; and 3) As used with respect to the certification of aircraft engines means those engines which are similar in design. For example, JT8D and JT8D7 are engines of the same type, and JT9D-3A and JT9D-7 are engines of the same type. (14CFR1)
Type of Drive	Refers to which wheels the engine power is delivered to, the so-called "drive wheels." Rear-wheel drive, has drive wheels on the rear of the vehicle. Front-wheel drive, a newer technology, has drive wheels on the front of the vehicle. Four-wheel drive uses all four wheels as drive wheels, and is found mostly on Jeep-like vehicles and trucks, though it is becoming increasingly more common on station wagons and vans. (DOE4) (DOE5)
Type of Occurrence	(See also Accident) The highest level of an accident classification mechanism known as the sequence of events. (NTSB1) (NTSB2)
Type of Primary Service	The dominant type of service the respondent uses at the service station. Response categories include Full-Service Pumps, "Self-or Mini-Service Pumps," or " Both Equally." Mini Service is provided when attendants pump the vehicle fuel but do not provide any other service, such as checking the tire pressure or washing windshields. (DOE4)
Types of Goods Carried By Inland Waterways	The categories of goods carried by inland waterways are those defined by the NST/R (Standard Goods Nomenclature for Transport Statistics/revised EUROSTAT) or CSTE (UN-ECE Commodity Classification for Transport Statistics in Europe) nomenclatures. (TNDOT1)
U.S. Flag Carrier or American Flag Carrier (Air)	One of a class of air carriers holding a Certificate of Public Convenience and Necessity, issued by the U.S. Department of Transportation and approved by the President, authorizing scheduled operations over specified routes between the United States (and/or its territories) and one or more foreign countries.
Ullage	See Outage.
Ultra-Low Emission Vehicle	A lean fuel vehicle meeting the more stringent Ultra-low emission standards. (DOE6)
Under Construction Road	Road construction has begun but is not completed. (DOI3)
Under Construction Runway	Construction has begun but is not completed. (DOI3)
Underneath the Point	Directly below and downstream from the point of land. (TNDOT1)
Underpass	The grade separation where part or all of one feature instance is directly above part or all of another feature instance. (DOI3)
Undredged Shipping Lane	Lane has not been dug out. (DOI3)
Unfinished Oil	Includes all oils requiring further processing, except those requiring only mechanical blending. In most cases, these are produced by partial refining or purchased in an unfinished state for conversion to finished products by further refining. (DOE5)
Unified Planning Work Program (UPWP)	The management plan for the (metropolitan) planning program. Its purpose is to coordinate the planning activities of all participants in the planning process.
Union of Soviet Socialist Republic (U.S.S.R)	Consisted of 15 constituent republics Armenia, Azerbaijan, Belarus, Estonia, Georgia, Kazakhstan, Kyrgystan, Latvia, Lithuania, Moldava, Russia, Tajikistan, Turkmenistan, Ukraine, and Uzbekistan. As a political entity, the U.S.S.R. ceased to exist as of December 31, 1991. (DOE3)
Unit Load	Packages loaded on a pallet, in a crate or any other way that enables them to be handled at one time as a unit. (MARAD2)
Unit Load Device	Any type of freight container, aircraft container, aircraft pallet with a net, or aircraft pallet with a net over an igloo. (49CFR171)
Unit Tow	An integrated tow consisting of bow, center, and stem sections. Found generally in the liquid cargo trade. (TNDOT1)
Unit Train	A train of a specified number of railcars handling a single commodity type which remain as a unit for a designated destination or until a change in routing is made.
United States (U.S.) Flag Carrier (or American Flag Carrier)	One of a class of air carriers holding a Certificate of Public Convenience and Necessity issued by the DOT, approved by the President, authorizing scheduled operations over specified routes between the United States (and/or its territories) and one or more foreign countries. (FAA2) (FAA14)
United States (U.S.) Territories	Include Samoa, Guam, the Northern Marianas, Puerto Rico and the Virgin Islands. (FHWA2)
United States Air Carrier	A citizen of the United States who undertakes directly by lease, or other arrangement, to engage in air transportation. (14CFR1)
United States Code	Contains a consolidation and codification of all general and permanent laws of the U.S. (USCG1)
United States Travel and Tourism Administration (USTTA)	An agency in the Commerce Department; it's principal mission is to implement broad tourism policy initiatives for the development of international travel to the U.S. as a stimulus for economic stability. (USTTA1)
Unladen Inland Waterways Traffic	Any movement of an Inland Waterways Transport (IWT) freight vessel for which the gross weight of goods carried, including that of equipment such as containers, swap-bodies and pallets, is nil; as well as any movement of an IWT passenger vessel without passengers. (TNDOT1)
Unlatch	Release lock on fifth wheel to drop trailer. (ATA1)
Unlinked Passenger Trips	The number of passengers who board public transportation vehicles. A passenger is counted each time he/she boards a vehicle even though he/she may be on the same journey from origin to destination. (APTA1) (FTA1)
Unlinked Passenger Trips (Transit)	The number of passengers boarding public transportation vehicles. A passenger is counted each time he/she boards a vehicle even if the boarding is part of the same journey from origin to destination.
Unloaded Vehicle Weight	The weight of a vehicle with maximum capacity of all fluids necessary for operation of the vehicle, but without cargo, occupants, or accessories that are ordinarily removed from the vehicle when they are not in use. (49CFR571)
Unpaved Road Surface	Gravel/soil and unimproved roads and streets (Surface/Pavement Type Codes 20, 30 and 40). (FHWA2)
Unsatisfactory Condition Classification	Facility is not operational and is not serving the purpose for which it was constructed. (DOI2)
Unscheduled Repair	Maintenance requiring the emergency repair of a piece of equipment as distinguished from those repairs performed during a scheduled cycle. (GSA2)
Up the Hill	Anything away from the towboat and on shore. When a river man has "gone up the hill," he has gone ashore, whether it be in a city or on a mountainside or across a prairie. (TNDOT1)
Up-and-Down Rod	[with respect to rail operations] A rod used for connecting the semaphore arm to the operating mechanism of a signal. (49CFR236)
Upper Coupler Assembly	A structure consisting of an upper coupler plate, king-pin and supporting framework which interfaces with and couples to a fifth wheel. (49CFR393)
Upper Coupler Plate	A plate structure through which the king-pin neck and collar extend. The bottom surface of the plate contacts the fifth wheel when coupled. (49CFR393)
Upper Gage	A water level gage located at the upper end of the lock. (TNDOT1)
Upper-Half of Saddle-Mount	(See also King-Pin Saddle-Mount, Lower-Half of Saddle-Mount, Saddle-Mount) That part of the device which is securely attached to the towed vehicle and maintains a fixed position relative thereto, but does not include the "king-pin." (49CFR393)
Urban	Usually refers to areas with population of 5,000 or greater. (DOE6)
Urban Area	Any area that includes a municipality or other built up place which is appropriate, in the judgement of the Secretary of Transportation, for a public transportation system to serve commuters or others in the locality taking into consideration the local patterns and trends of urban growth. (FTA1)
Urban Arterial Routes	Those public roads that are functionally classified as a part of the urban principal arterial system or the urban minor arterial system as described in volume 20, appendix 12, Highway Planning Program Manual. (23CFR470)
Urban Collector Routes	Those public roads that are functionally classified as a part of the urban collector system as described in volume 20, appendix 12, Highway Planning Program Manual. (23CFR470)
Urban Ferryboat	A boat providing fixed-route service across a body of water with one or more terminals within an urbanized area, excluding international and urban park ferries. (APTA1)
Urban Highway	Any road or street within the boundaries of an urban area. An urban area is an area including and adjacent to a municipality or urban place with a population of 5,000 or more. The boundaries of urban areas are fixed by state highway departments, subject to the approval of the Federal Highway Administration, for purposes of the Federal-Aid Highway Program.
Urban Inland Waterways Transport	Transport carried out on inland waterways located within the boundaries of a built-up area. (TNDOT1)
Urban Place	A U.S. Bureau of Census-designated area consisting of incorporated political units or closely settled unincorporated areas outside an urbanized area. (APTA1)
Urbanized Area	Area that contains a city of 50,000 or more population plus incorporated surrounding areas meeting size or density criteria as defined by the U.S. Census.
Urbanized Area Formula Program Funds	Financial assistance from the Urbanized Area Formula Program (formerly Section 9). This program governs the distribution of the public transit capital and operating block grant appropriations by urbanized area. For this form, it is the Federal capital assistance granted to public transit agency providers to designated recipients on behalf of transit providers. (FTA1)
Used Vehicle	A vehicle with prior use. (49CFR37)
Useful Thermal Output	The thermal energy made available for use in any industrial or commercial process or used in any heating or cooling application, i.e., total thermal energy made available for processes and applications other than electrical generation. (DOE5)
User	The external individual or group that receive services from the National Airspace System (NAS) (e.g., Pilot, Air Carrier, General Aviation, Military, Law Enforcement Agencies, etc.). (FAA8)
User Charge	A fee charged to users for goods and services provided by the federal, state and local governments. User charges, either directly or indirectly, are paid on a periodic or occasional basis with license fees and excises. User charges are also paid at the time infrastructure services are consumed with the payment of fuel taxes and tolls. (BTS3)
User-Preferred Trajectory	The route, altitude profile, speed, and times of departure and arrival that the user prefers. (FAA7)
Utility Aircraft	An aircraft designed for general purpose flying. (AIA1)
Utility Airport	An airport designed, constructed, and maintained to serve airplanes in Aircraft Approach Category A and B. (FAA12)
Utility Employee	A railroad employee assigned to and functioning as a temporary member of a train or yard crew whose primary function is to assist the train or yard crew in the assembly, disassembly or classification of rail cars, or operation of trains (subject to the conditions set forth in 49CFR218.22. (49CFR218)
Vacuum Assist Power Brakes	Standard type hydraulic brakes with a pressure assist cylinder having a vacuum chamber which when atmospheric pressure is allowed to one side of the piston or diaphragm, drives a plunger in the hydraulic system thereby increasing the effect of pedal pressure. (TII1) (TII2)
Value of Property Assisted	Monetary value of the distressed unit (including cargo) at the time assistance was rendered by the Coast Guard. (USCG3)
Value of Property Lost	Monetary value of actual property lost as a result of the incident. (USCG3)
Van	See also Motor Vehicle, Vehicle.
Vanning	A term for stowing cargo in a container. (MARAD2)
Vanpool	Vans and/or Class C motor buses operating as a voluntary commuter ride sharing arrangement, which provides transportation to a group of individuals traveling directly between their homes and their regular places of work within the same geographical area. The vans should have a seating capacity greater than seven persons, including the driver. (FTA1)
Vanpool (Transit)	Public-sponsored commuter service operating under prearranged schedules for previously formed groups of riders in 8- to 18-seat vehicles. Drivers are also commuters who receive little or no compensation besides the free ride.
Vaporization	An addition of thermal energy changing a liquid or semisolid to a vapor or gaseous state. (49CFR193)
Vaporizer	A heat transfer facility designed to introduce thermal energy in a controlled manner for changing a liquid or semisolid to a vapor or gaseous state. (49CFR193)
Variable Operating Cost	In reference to passenger car operating cost, expenditures which are dependent on the amount of use of the car, such as the cost of gas and oil, tires, and other maintenance. (DOE6)
Vehicle	See also Automobile, Bus, Car, Minivan, Moped, Motorcycle, Motor Vehicle, Semi, Semitrailer, Taxi, Tractor Trailer, Tractor-Semitrailer, Truck, Truck Tractor, Van.
Vehicle Acquisition	(See also Vehicle Disposition) The number of vehicles a household acquires or obtains during the year. The average number of vehicles in the stock is computed using these data. (DOE4) (DOE5)
Vehicle Class	A term that includes sedans, station wagons, ambulances, buses and trucks, or different categories of vehicles according to Federal Standards for fiscal year 1992. (GSA1)
Vehicle Configuration	The combination of vehicular units comprising a commercial motor vehicle. (FHWA4)
Vehicle Disposition	(See also Vehicle Acquisition) The number of vehicles a household disposes of during the survey year. Disposed vehicles include those sold, traded, or the owner moved out of the household. The average number of vehicles in the stock is computed using these data. (DOE4)
Vehicle Fuel	(See also Fuel, Gasohol, Gasoline, Kerosene) The predominant type of fuel purchased during 1991. Data categories are leaded and unleaded gasoline, diesel motor fuel and "other" which includes propane and gasohol. (DOE5)
Vehicle Fuel Consumption	Vehicle fuel consumption is computed as the vehicle miles traveled divided by the fuel efficiency reported in MPGs. Vehicle fuel consumption is derived from the actual vehicle mileage collected and the assigned MPGs obtained from Environmental Protection Agency (EPA) certification files adjusted for on-road driving. The quantity of fuel used by vehicles. (DOE5)
Vehicle Fuel Expenditures	The cost, including taxes, of the gasoline, gasohol, or diesel fuel added to the vehicle's tank. Expenditures do not include the cost of oil or other items that may have been purchased at the same time as the vehicle fuel. (DOE4) (DOE5)
Vehicle Fuel Tank Capacity	The tank's unusable capacity (i.e.,the volume of fuel left at the bottom of the tank when the vehicle's fuel pump can no longer draw fuel from the tank) plus its usable capacity (i.e., the volume of fuel that can be pumped into the tank through the filler pipe with the vehicle on a level surface and with the unusable capacity already in the tank). The term does not include the vapor volume of the tank (i.e., the space above the fuel tank filler neck) nor the volume of the fuel tank filler neck. (49CFR571)
Vehicle Identification Number (VIN)	A set of about 17 codes, combining letters and numbers, assigned to a vehicle at the factory and inscribed on a small metal label attached to the dashboard and visible through the windshield. The vehicle identification number (VIN) is a unique identifier for the vehicle and therefore is often found on insurance cards, vehicle registrations, vehicle titles, safety or emission certificates, insurance policies, and bills of sale. The coded information in the VIN describes characteristics of the vehicle such as engine size and weight. (DOE4) (DOE5)
Vehicle In Use	All vehicles in the inventory that are permanently assigned to an agency or in paid seasonal storage. (GSA2)
Vehicle Kilometer	Unit of measurement of traffic representing the movement of an individual Inland Waterways Transport (IWT) vessel or convoy over one kilometer. (TNDOT1)
Vehicle Maintenance	All activities associated with revenue and non-revenue (service) vehicle maintenance, including administration, inspection and maintenance, and servicing (cleaning, fueling, etc.) vehicles. In addition, it includes repairs due to vandalism, and accident repairs of revenue vehicles. (FTA1)
Vehicle Maintenance (Transit)	All activities associated with revenue and nonrevenue (service) vehicle maintenance, including administration, inspection and maintenance, and servicing (e.g., cleaning and fueling) vehicles. In addition, it includes repairs due to vandalism or to revenue vehicle accidents.
Vehicle Maneuver	(See also Crash, Vehicle Role) Last action (maneuver) this vehicle's driver engaged in either 1) just prior to the impact or 2) just before the driver realized the impending danger. (NHTSA1)
Vehicle Mile of Travel (VMT)	A unit to measure vehicle travel made by a private vehicle, such as an automobile, van, pickup truck, or motorcycle. Each mile traveled is counted as one vehicle mile regardless of the number of persons in the vehicle. (FHWA3)
Vehicle Miles	Vehicle miles are the miles of travel by all types of motor vehicles as determined by the States on the basis of actual traffic counts and established estimating procedures. (FHWA5)
Vehicle Miles of Travel (VMT)	The number of miles traveled nationally by vehicles for a period of 1 year. VMT is either calculated using 2 odometer readings or, for vehicles with less than 2 odometer readings, imputed using a regression estimate. (DOE5)
Vehicle Miles Operated	Sum of all miles operated by passenger vehicles, including mileage when no passengers are carried. When vehicles are operated in trains, each vehicle is counted separately-e.g., an eight-vehicle train operating for one mile equals eight vehicle miles. (APTA1)
Vehicle Occupancy	The number of persons, including driver and passenger(s) in a vehicle; also includes persons who did not complete a whole trip. Nationwide Personal Transportation Survey (NPTS) occupancy rates are generally calculated as person miles divided by vehicle miles. (FHWA3)
Vehicle On Hand	All vehicles for which General Services Administration (GSA) has accountability. (GSA2)
Vehicle Operations	All activities associated with the subcategories of the vehicle operations function transportation administration and support; revenue vehicle operation; ticketing and fare collection; and system security. (FTA1)
Vehicle Operations (Transit)	All activities associated with transportation administration, including the control of revenue vehicle movements, scheduling, ticketing and fare collection, system security, and revenue vehicle operation.
Vehicle Revenue Miles/Hours	The miles/hours a vehicle travels while in revenue service. A transit vehicle is in revenue service only when the vehicle is available to the public and there is a reasonable expectation of carrying passengers that either directly pay fares, are subsidized by public policy, or provide payment through some contractual arrangement. This does not imply that a cash fare must be paid. Vehicles operated in free fare service are considered in revenue service. Vehicle revenue miles/hours exclude travel to and from storage facilities, training operators prior to revenue service, road tests and deadhead travel, as well as school bus and charter services. (FTA1)
Vehicle Role	(See also Crash, Vehicle Maneuver) Role of vehicle in single or multi-vehicle crashes (i.e., non-collision, striking, and struck). (NHTSA1)
Vehicle Stock	The number of vehicles owned or used by a household for personal transportation. A vehicle is defined in terms of a "Vehicle Year." If a vehicle is present in a household for the entire year, it counted as one vehicle. If a vehicle is present in a household for one-half of the year, it is counted as only one-half of a vehicle. Therefore, the number of vehicles a sample household was considered as having during the year was computed as the days of possession summed over all vehicles in the household, divided by days in a year. (DOE4) (DOE5)
Vehicle Trip	A trip by a single vehicle regardless of the number of persons in the vehicle. (FHWA3)
Vehicle Type	A series of motor vehicle body types that have been grouped together because of their design similarities. (NHTSA1) (NHTSA3)
Vehicle Used On the Job	A vehicle used by anyone in the household for job-related activities, excluding commuting to and from work. (DOE4) (DOE5)
Vehicle/Pedestrian Deviation (VPD)	(See also Operational Deviation, Operational Error, Pilot Deviation, Runway Incursion) An entry or movement on an airport movement area by a vehicle operator or pedestrian that has not been authorized by air traffic control (includes aircraft operated by a non-pilot). (FAA3) (FAA10)
Vehicle-Miles (Highway)	Miles of travel by all types of motor vehicles as determined by the states on the basis of actual traffic counts and established estimating procedures.
Vehicle-Miles (Transit)	The total number of miles traveled by transit vehicles. Commuter rail, heavy rail, and light rail report individual car-miles, rather than train-miles for vehicle-miles.
Vehicle-Miles Traveled (VMT)	One vehicle traveling the distance of one mile. Total vehicle miles, thus, is the total mileage traveled by all vehicles. (DOE6)
Vehicles Available For Maximum Service	The number of revenue vehicles available to meet the annual maximum service requirements. This includes spares, out-of-service vehicles, and vehicles in or awaiting maintenance, but excludes vehicles awaiting sale and emergency contingency vehicles. (FTA1)
Vehicles in Total Fleet	All revenue vehicles held at the end of the fiscal year, including those in storage, emergency contingency and awaiting sale. (FTA1)
Vehicles Operated In Maximum Service	The number of revenue vehicles operated to meet annual maximum service requirements. This is the revenue vehicle count during the peak season of the year, on the week and day that maximum service is provided. Vehicles operated in maximum service exclude atypical days or one-time special events. (FTA1)
Very High Frequency (VHF) Communications	Provides radio voice communications between aircraft and ground stations, also between aircraft. Very High Frequency (VHF) is limited in angle (line of sight) and usually used for air traffic communications. (FAA6)
Very High Frequency Omnidirectional Radio Range (VOR)	Used as the basis for navigation in the National Airspace System. (FAA2) (FAA6)
Very Large Crude Carrier (VLCC)	A crude oil carrying ship of between 160,001 and 320,000 deadweight tons. (DOE5)
Vessel	Tankers used to transport crude oil and petroleum products. Vessel categories are as follows Ultra Large Crude Carrier (ULCC), Very Large Crude Carrier (VLCC), Other Tanker, and Specialty Ships Liquefied Petroleum Gas (LPG)/Liquefied Natural Gas (LNG). (DOE5)
Vessel Bunkering	Includes sales for the fueling of commercial or private boats, such as pleasure craft, fishing boats, tugboats, and ocean-going vessels, including vessels operated by oil companies. Excluded are volumes sold to the U.S. Armed Forces. (DOE5)
Vessel Casualty (Water)	An occurrence involving commercial vessels that results in 1) actual physical damage to property in excess of $25,000; 2) material damage affecting the seaworthiness or efficiency of a vessel; 3) stranding or grounding; 4) loss of life; or 5) injury causing any person to remain incapacitated for a period in excess of 72 hours, except injury to harbor workers not resulting in death and not resulting from vessel casualty or vessel equipment casualty.
Vessel Kilometer	Unit of measurement representing the movement of an Inland Waterways Transport (IWT) vessel over one kilometer. (TNDOT1)
Vessel-Casualty-Related Death (Water)	Fatality that occurs as a result of an incident that involves a vessel or its equipment, such as a collision, fire, or explosion. Includes drowning deaths.
Visioning	A variety of techniques that can be used to identify goals.
Visual Flight Rules (VFR)	Rules that govern the procedures for conducting flight under visual conditions. The term (VFR) is also used in the U.S. to indicate weather conditions that are equal to or greater than minimum Visual Flight Rules (VFR) requirements. In addition, it is used by pilots and controllers to indicate type of flight plan. (FAA13) (FAA14)
Visual Flight Rules (VFR) Conditions	Weather conditions equal to or better than the minimum for flight under visual flight rules. (FAA8)
Visual Flight Rules (VFR) Flight	Flight conducted in accordance with Visual Flight Rules. (FAA2) (FAA10)
Visual Flight Rules (VFR) Over-The-Top	With respect to the operation of aircraft, means the operation of an aircraft over-the-top under Visual Flight Rules (VFR) when it is not being operated on an Instrument Flight Rules (IFR) flight plan. (14CFR1)
Visual Flight Rules (VFR) Terminal Area Charts	Depict Class B airspace which provides for the control of segregation of all the aircraft within Class B airspace. The chart depicts topographic information and aeronautical information which includes visual and radio aids to navigation, airports, controlled airspace, restricted areas, obstructed and related data. (FAA4)
Visual Flight Rules (VFR) Tower	An airport traffic control tower providing takeoff and landing services only. It does not provide approach control services. (FAA10) (FAA13) (FAA14)
Visual Meteorological Conditions (VMC)	Meteorological conditions expressed in terms of visibility, distance from cloud, and ceiling equal to or better than the specified minima. (FAA8)
Visual Runway	A runway without an existing or planned straight in instrument approach procedure. (FAA12)
Volatile Organic Compounds (VOCs)	VOCs come from vehicle exhaust, paint thinners, solvents, and other petroleum-based products. A number of exhaust VOCs are also toxic, with the potential to cause cancer.
Walk	To use the rudders opposite to the screws so as to cause the tow to move sideways in close maneuvering. (TNDOT1)
Walking	A colloquial term for a flanking maneuver. (TNDOT1)
War Risk	The possible aggressive actions against a ship and its cargo by a belligerent government. This risk can be insured by a marine policy with a war risk clause. (TNDOT1)
Warehouse	A place for the reception, delivery, consolidation, distribution, and storage of goods/cargo. (MARAD2)
Warning Area	Airspace which may contain hazards to non participating aircraft in international airspace. (FAA8)
Warranty	The written guarantee issued with new motor vehicles or related equipment. It defines the manufacturer's responsibility for the repair or replacement of defective parts and other services provided as part of the purchase price. A warranty can be nullified if the user does not follow certain stipulations of the manufacturer, such as preventive maintenance. (GSA2)
Wash	The usually dry portion of a bed of a stream that contains water only during or after a local rainstorm or heavy snowmelt. (DOI3)
Waste and Tar Oils	Petroleum-based materials that are worthless for any purpose other than fuel use. (DOE5)
Water	See also Waterway.
Water Intake/Outflow	A structure through which water enters or exits a conduit. (DOI3)
Water Mode	Consists of navigable rivers, canals, the Great Lakes, the St. Lawrence Seaway, the Intercoastal Waterway, ocean shipping channels; ports; commercial ships and barges, fishing vessels, urban ferries, and recreational boats. (BTS1) (BTS2)
Water Pollution Abatement Equipment	Equipment used to reduce or eliminate waterborne pollutants, including chlorine, phosphates, acids, bases, hydrocarbons, sewage, and other pollutants. Examples of water pollution abatement structures and equipment include those used to treat thermal pollution; cooling, boiler, and cooling tower blowdown water; coal pile runoff; and fly ash waste water. Water pollution abatement excludes expenditures for treatment of water prior to use at the plant. (DOE5)
Water Transportation	Includes establishments engaged in freight or passenger transportation on the open seas or inland waters, and establishments that provide incidental services such as lighterage, towing, and canal operation. Also includes excursion, sightseeing, water taxis, and cargo handling. (BEA1)
Water Transportation of Freight (Not Elsewhere Classified)	Establishments primarily engaged in transporting freight on all inland waterways, including the intracoastal waterways on the Atlantic and Gulf coasts. (BOC1)
Water Transportation of Passengers (Not Elsewhere Classified)	Establishments primarily engaged in furnishing water transportation of passengers, not elsewhere classified, such as airboats (swamp buggy rides), excursion boat operations, and sightseeing boats. (BOC1)
Waterborne Transportation	Transport of freight and/or people by commercial vessels under U.S. Coast Guard jurisdiction.
Watercourse	A way or course through which water may or does flow. (DOI4)
Waterfront Liquid Natural Gas (LNG) Plant	An LNG plant with docks, wharves, piers, or other structures in, on, or immediately adjacent to the navigable waters of the United States or Puerto Rico and any shore area immediately adjacent to those waters to which vessels may be secured and at which LNG cargo operations may be conducted. (49CFR193)
Watering Place	A place other than a spring or well where vessels and vehicles replenish their water supply. (DOI4)
Waters of the U.S.	The territorial seas; coastal and inland waters, lakes, rivers, and streams that are navigable waters of the United States, including adjacent wetlands; tributaries to navigable waters of the United States, including adjacent wetlands (man-made non-tidal drainage and irrigation ditches excavated on dry land are not considered to be tributaries); interstate waters and their tributaries, including adjacent wetlands; all other waters of the United States such as isolated wetlands and lakes, intermittent streams, prairie potholes, and other waters that are not part of a tributary system to interstate waters or to navigable waters of the United States, the degradation or destruction of which could affect interstate commerce. (TNDOT1)
Waterway	River, canal, lake or other stretch of water that by natural or man-made features is suitable for navigation. (DOE5)
Waybill	A document that lists goods and shipping instructions relative to a shipment.
Weather Radar	Provides the flight crew with visual display of weather that could contain turbulence. The system's primary function is to assist in turbulence avoidance, although most airborne radar systems are also capable of terrain mapping. (FAA6) (FAA10)
Weekday	From 6 a.m. Monday to 5:59 p.m. Friday. (NHTSA3)
Weekend	From 6 p.m. Friday to 5:59 a.m. Monday. (NHTSA3)
Weigh Facility	An area having facilities for weighing of trucks by State highway authority. (DOI3)
Weight Ton	There are three types of weight tons; 1) The short ton, weighing 2,000 pounds; 2) The long ton, weighing 2,240 pounds; and 3) The metric ton, weighing 2,204.68 pounds. The last is frequently quoted for cargo being exported from Europe. (TNDOT1)
Weight/Measurement Ton	In many cases, a rate is shown per weight/measurement ton, carrier's option. This means that the rate will be assessed on either a weight ton or measurement ton basis, whichever will yield the carrier the greater revenue. For example, the rate may be quoted on the basis of 2,240 pounds or 40 cubic feet or 1 metric ton or 1 cubic meter. (TNDOT1)
Weight-Distance Tax	A tax basing the fee per mile on the registered gross weight of the vehicle. Total tax liability is calculated by multiplying this rate times miles traveled. (ATA2)
Weir	(See also Low Water Dam) A dam in a waterway over which water flows and that serves to raise the water level or to direct or regulate flow. (DOE5)
Well Area	An area identified as a danger to maritime navigation containing one or more wells. (DOI3)
Well Out In River	Channel report term meaning nearer to the middle of the river than to the bank. (TNDOT1)
Wellhead Unit Value	The wellhead sales price, including charges for natural gas plant liquids subsequently removed from the gas; gathering and compression charges; and state production, severance, and/or similar charges. (DOE5)
Western Rivers	Generally, the Mississippi River system but technically the Mississippi River system above the Huey P. Long Bridge, the Red River to the north, the Port Allen-Morgan City Waterway, and that part of the Atchafalaya River above its junction with the Port Allen-Morgan City Waterway. (TNDOT1)
Wharf	See also Dock, Marina, Pier.
Wharf Demurrage	Charge assessed against cargo remaining in or on terminal facilities after the expiration of free time, unless arrangements have been made for storage. (MARAD1)
Wharfage	(See also Berth, Dockage) Charge assessed by a pier or dock owner against freight handled over the pier or dock or against a steamship company using the pier or dock. (MARAD2)
Wheelbase	The distance from the center line of the front axle to the center line of the rear axle. (GSA2)
Wheelchair	A mobility aid belonging to any class of three or four wheeled devices, usable indoors, designed for and used by individuals with mobility impairments, whether operated manually or powered. A "common wheelchair" is such a device which does not exceed 30 inches in width and 48 inches in length measured two inches above the ground, and does not weigh more than 600 pounds when occupied. (49CFR37)
Wheelchair Accessible Vehicle	A vehicle that a wheelchair-bound person may enter either 1) via an on-board retractable lift or ramp; 2) directly from a station platform reached by an elevator or a ramp that is either level with the vehicle floor or can be raised to floor level. (APTA1)
When Halfway Over	Channel report term used in crossings meaning when halfway across the river, put head of tow on the next mark listed in the channel report. (TNDOT1)
When Well Over	Channel report term used in describing courses steered in crossings when more than halfway across or halfway over the reach. (TNDOT1)
Wicket	A rectangular heavily constructed slab of wood and steel hinged in a counterbalanced way so as to be lying flat on the riverbed when down, and held upright by the pressure of the water when raised. Wickets are placed in a parallel line across the river. When all are in raised position, they form a wall or dam, thus backing up the water and raising it to the pool level. (TNDOT1)
Wide Out	A channel report term meaning not quite as far as the middle but well out in the channel. (TNDOT1)
Wide Reef	An illusion caused by the wind blowing upstream against the current. There is generally a deep trench under the ripples caused by the wind. (TNDOT1)
Wide Spread	Trailer axles which are more than 8 feet apart. (ATA1)
Winch Rig	Straight truck or tractor with a hoist. (ATA1)
Wind Indicator	A visual device used to provide wind information. (DOI4)
Windbreak	A shelter, either natural (e.g., a line of trees or a thick hedge) or artificial (a screen), which breaks or interrupts the force of the wind. (DOI4)
Windshield	The combination of individual units of glazing material of the locomotive, passenger car, or caboose that are positioned in an end facing glazing location. (49CFR223)
Wingboard	A 12-by 36-inch daymark formerly used with type 46 wooden structures. Wingboards are now being replaced by passing daymark. (TNDOT1)
Wingdam	A rock and sand dike extending from the right or left bank of the river outward toward the channel. Often lies just below the surface of the water at pool stage. Wingdams are used to direct the flow of water into the main channel to assist in its maintenance. (TNDOT1)
Winglet (Tip Fin)	An out-of-plane surface extending from a lifting surface. The surface may or may not have control surfaces. (14CFR1)
Wires	Short lengths of wire rope of varying sizes used to couple up the many barges within a tow. They are usually of standard length to span the distance from one timberhead to another on the barges and are used with ratchets. Named as follows tow wire, backing wire, face wire, stem wire, scissor wire, lashing. (TNDOT1)
With Average	A marine insurance term meaning that a shipment is protected for partial damage whenever the damage exceeds a stated percentage. (TNDOT1)
Wood Hull	Hulls of plywood, molded plywood molded planking, or any other wood fiber in its natural consistency including those of wooden construction that have been "sheathed" with fiberglass or sheet metal. (USCG2)
Woodchuck	Driver with low job seniority. (ATA1)
Wooden Barrel	A packaging made of natural wood, of round cross-section, having convex walls, consisting of staves and heads and fitted with hoops. (49CFR171)
Work Barge	A barge equipped with aids to navigation material pushed ahead of the tender and containing storage space for lumber, sinkers, buoys, an aids to navigation workshop, and a boom for hoisting buoys on board. (TNDOT1)
Work Environment	The work environment is comprised of the physical location, equipment, materials processed or used, and the activities of an employee while engaged in the performance of his work, whether on or off the railroads property. There are no stated exclusions of place or circumstance. (FRA2)
Work Equipment	Equipment which can be coupled in a train for movement over the carrier's tracks, and which is used in the carrier's work service. Includes such equipment as ballast cars, business cars, company cars, derrick cars, ditching cars, outfit cars, pile drivers, snow dozers, tool cars, wrecking cars, and others. (AAR1)
Work Train	Work trains are non-revenue trains used for the administration and upkeep service of the railroad. Examples are official trains; inspection trains; special trains running with company fire apparatus to save the railroad's property from destruction; trains that transport the railroad's employees to and from work when no transportation charge is made; construction and upkeep trains run in connection with maintenance and improvement work; and material and supply trains run in connection with operations. (FRA2)
Worker	Any railroad employee assigned to inspect, test, repair, or service railroad rolling equipment, or their components, including brake systems. Members of train and yard crews are excluded except when assigned such work on railroad rolling equipment that is not part of the train or yard movement they have been called to operate (or been assigned to as "utility employees"). Utility employees assigned to and functioning as temporary members of a specific train or yard crew (subject to the conditions set forth in 49 CFR 218.22), are excluded only when so assigned and functioning. (49CFR218)
Work-Related	Any event, exposure, activity, etc., occurring within the work environment resulting in death, injury, illness to an employee is generally considered to be work-related, regardless who was responsible or at fault. (FRA2)
World Aeronautical Charts (WAC)	Provide a standard series of aeronautical charts covering land areas of the world at a size and scale convenient for navigation by moderate speed aircraft. Topographic information includes cities and towns, principal roads, railroads, distinctive landmarks, drainage and relief. Aeronautical information includes visual and radio aids to navigation, airports, airways, restricted areas, obstructions, and other pertinent data. (FAA4)
Worst Case Discharge	The largest foreseeable discharge of oil, including a discharge from fire or explosion, in adverse weather conditions. This volume will be determined by each pipeline operator for each response zone and is calculated according to 49 CFR 194.105. (49CFR194)
Wreck	A wrecked vessel, either submerged or visible, which is attached to or foul of the bottom or cast up on the shore. (DOI4)
Wreckage	An area identified as a danger to maritime navigation containing the ruined remains of one or more vessels. (DOI3)
Wrecker	Truck designed for hoisting and towing disabled vehicles. (ATA1)
Yard	A system of auxiliary tracks used exclusively for the classification of passenger or freight cars according to commodity or destination; assembling of cars for train movement; storage of cars; or repair of equipment. (49CFR223)
Yard Caboose	A caboose that is used exclusively in a single yard area. (49CFR223)
Yard Crew	See Train or Yard Crew.
Yard Locomotive	A locomotive that is operated only to perform switching functions within a single yard area. (49CFR223)
Yard Mule	Small tractor used to move semitrailers around the terminal yard. (ATA1)
Yard Switching Train Mile	Computed at the rate of 6 mph for the time actually engaged in yard switching service if actual mileage is not known. (FRA2)
Yard Switching Trains	Those trains operated primarily within yards for the purpose of switching other equipment. Examples include the making up or breaking up of trains, service industrial tracks within yard limits, storing or classifying cars, and other similar operations. Switching performed by a road crew that is incidental to the road operation is not included. (FRA2)
Yard Track	A system of tracks within defined limits used for the making up or breaking up of trains, for the storing of cars, and for other related purposes, over which movements not authorized by timetable, or by train order may be made subject to prescribed signals, rules or other special instructions. Sidings used exclusively as passing track and main line track within yard limits are not included in the term yard track. (49CFR245) (FRA2)
Yard Tractor	A truck tractor used exclusively to move trailers around a motor or trailer yard. It is not used for over the road travel. (BOC3)
Yardbird	(See also Spotter) A driver who connects and disconnects tractor and semitrailer combinations and moves vehicles around the terminal yard. (ATA1)
Yawl	(See also Skiff) A small oar-propelled open boat or skiff carried aboard a towboat for use as a utility boat. (TNDOT1)
Yawl Play	The use of a yawl to row lines or personnel between boat and bank. (TNDOT1)
Year of Construction	The year the structure was originally completed or the year any part of the structure was first occupied. For mobile homes year of construction is the model year. (DOE5)
Year of Construction of Vessel	Year of original construction of the hull. (TNDOT1)
Zephyr Haul	A shipment of light weight cargo. (ATA1)
Zero-Emission Vehicle	A clean fuel vehicle meeting even more stringent zero-emission vehicle standards. (DOE6)
Zone	The smallest geographically designated area for analysis of transportation activity. A zone can be from one to ten square miles in area. Average zone size depends on the total size of study area.
Zone Charge	An extra fee charged for crossing a predetermined boundary. (APTA1)

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