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Volpe Center Highlights - January/February 2002

Safety

Director's Notes | Focus | Safety | Mobility | Human and Natural Environment
Economic Growth | National Security | Papers and Presentations

Evaluating Locomotive Horn Sound Levels (FRA)

For the past several years, the Volpe Center has supported the Federal Railroad Administration's (FRA) Office of Research and Development and Office of Safety Enforcement in evaluating locomotive horn systems. This work was prompted by concerns about the audibility of locomotive horns at highway-rail grade crossings in modern sound-insulated highway vehicles, as well as by complaints of abutting residents who have protested excessive exposure to the sound of these horns.

Four horn installation locations were chosen for the study as representative of those either currently in service or being considered for service. Note that all horns were centered over the width of the locomotive.

Recent work responds to comments on the FRA Proposed Rule for the Use of Locomotive Horns at Highway-Rail Grade Crossings. Many comments were received on a particular provision within the rule stating that the sound level generated by the horn, when measured at the side of the locomotive, shall not exceed the sound level measured in front of the locomotive. In the late 1980s, it became the de facto standard to install horns on the top/center portion of the locomotive. This position was chosen in an attempt to reduce the noise exposure for the locomotive cab occupants. However, it resulted in measured sound levels to the side of the locomotive that were often higher than levels in front of the locomotive, and which increased noise level exposure to residences along the railway right-of-way. Consequently, this provision in the FRA's Proposed Rule may force railroad operators to relocate many installed horns.

The Environmental Measurement and Modeling Division performed a measurement study with the primary objective of documenting precisely the effect of installation location on the railroad horn sound level output at distances around the locomotive and inside the locomotive cab. The Volpe study recommended horn locations as far forward and high as possible in order to meet requirements that limit sound directed to the side while minimizing noise levels inside the cab.

At the 7th International Workshop on Railway Noise, held in Portland, Maine, from October 24 to 27, 2001, Ms. Amanda Rapoza presented "Analysis of Railroad Horn Detectability," based on this study.

Ongoing analyses will use the data measured as a part of this study to assess both the change in effect on community noise level and the change in effect on motorist warning. It is anticipated that, together, these analyses will provide the FRA with the empirical information necessary to write a final rule.

Enhancing the Safety Performance Analysis System (FAA)

The Federal Aviation Administration's (FAA) Flight Standards Service is responsible for certifying air operators, air agencies, and air personnel, and for implementing and enforcing the federal regulations that oversee the safety of passengers using commercial air operators. Flight Standards aviation safety inspectors use the automated Safety Performance Analysis System (SPAS) to monitor the performance of certificate holders and to identify those that pose a greater-than-normal safety risk. Volpe's Aviation Safety Division supports development of SPAS based on user needs and technological advances. Two recent upgrade releases incorporate improved capabilities for this decision support system that include enhanced: National Transportation Safety Board query and browse capability, aircraft profiles, operator performance measures, engine profiles, aircraft performance measures, and enhanced printing and display of query and browse result lists.

Improving Motor Carrier Safety with Data Management (FMCSA)

The Federal Motor Carrier Safety Administration's (FMCSA) strategic approach to improving motor carrier safety encompasses many objectives, one of which is to increase the safety performance of the carriers that are the worst offenders. A key component of this objective is the Performance and Registration Information Systems Management (PRISM) Program, a federal-state partnership that links federal safety performance ratings with state motor vehicle registrations.

The Volpe Center provides operation and maintenance support to PRISM's information system, which is housed at the Volpe Data Center.

While the registration systems of the partner states form the framework, PRISM's two major processes registration and enforcement work in parallel to identify motor carriers and hold them responsible for the safety of their operation. For a vehicle to be registered, the responsible carrier must be identified; and all interstate carriers must receive a US DOT number. Carriers with bad safety performance ratings are targeted for compliance reviews by FMCSA safety investigators and may incur sanctions up to and including being put out of service. Performance is improved through a comprehensive system of identification, education, awareness, safety monitoring, and treatment; this approach is highly effective from a cost as well as a safety perspective.

The Volpe Center has been actively involved in PRISM operations over the past several years, including analytical and development support for SafeStat, a critical element of the PRISM improvement process. SafeStat is an automated performance analysis system that identifies carriers with potential safety problems and prioritizes them for an on-site review. Currently, the Center provides technology management of SafeStat and technical support to the FMCSA and its partner states in the operation and maintenance of the PRISM information system. Since April of 2001, the PRISM system has been housed in the Volpe Center Data Center. Twenty states are in various stages of PRISM implementation, and others are expected to join the program.

On November 27 and 28, 2001, Mr. Bob Berk and Ms. Rosemarie Kelly of Volpe's Computer Center hosted a PRISM Data Systems Meeting for the FMCSA. Attendees included FMCSA headquarters and field personnel, state motor vehicle registration and information technology staff, and state contractor personnel. The intent of the meeting was to resolve numerous technical issues arising from the inclusion of additional states in PRISM; to disseminate up-to-date information on PRISM, including new system specifications developed by the Volpe Center; and to answer questions and concerns from the user community.

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