MARCH 1999 U.S. BUREAU OF THE CENSUS VTDP Annotation TIGER/Line(R) (Also known as the TIGER/Line 1998) Census TIGER(R) and TIGER/Line(R) are registered trademarks of the U.S. Bureau of the Census. WHAT ARE TIGER/LINE FILES The TIGER/Line files were created from the Census Bureau's TIGER (Topologically Integrated Geographic Encoding and Referencing) data base of selected geographic and cartographic information. TIGER was developed at the Census Bureau to support the mapping and related geographic activities required by the decennial census and sample survey programs. TIGER/Line files are made available to the public and are typically used by people to provide the digital map base for their Geographic Information System or mapping software. This CD-ROM does not contain software to display or generate maps. Nor is the data on this CD-ROM in the form of a map image. To create maps with the data on this CD-ROM, one would typically use a Geographic Information System package or other mapping software. For information on how to use the TIGER/Line data with a specific package one should contact the company that produced the package. For information on companies that sell products that use TIGER/Line data or that provide various TIGER/Line-related services refer to the "Vendor's List" on the TIGER Page at the Census Bureau's World Wide Web site described below. WHAT'S NEW These TIGER/Line files are produced for use by the states participating in the Census 2000 Redistricting Data Program, Phase 2, the Voting District Project (VTDP) to submit their voting districts to the U. S. Census Bureau. The 1998 TIGER/Line files include approved submissions and updates from Phase 1, the Block Boundary Suggestion Project (BBSP), the 1998 Boundary and Annexation Survey, and other Census Bureau programs that update the TIGER data base. It is important to note that even though each TIGER/Line file represents a whole county, all new features in existence may not have been added in this release. The extent of updates in any given county will vary by program, number of participants, type of participant, time of participation, and a given participant's degree of participation in a program. USING THIS CD-ROM The 1998 TIGER/Line CD-ROMs contain digital cartographic data files and related documentation. The files include the counties, parishes, boroughs, census geographic areas, and equivalent entities for each state (or territory, and so forth) participating in the VTDP program. The data is organized in subdirectories by county (or county equivalent) within a state. Each state subdirectory is named using the two-digit FIPS code and the Post Office abbreviation for the state (ex. 02_AK for Alaska). Within the state subdirectory each county file has the name TGRssccc.ZIP, where the "ss" is the state FIPS code and "ccc" is the county FIPS code. The data for each county is stored in this single compressed file that when decompressed results in up to 17 separate files representing each of the TIGER/Line record types that exist for that county. Some counties did not require all of the 17 record types and therefore will have less than 17 files. If the types of data contained in record types 4, 6, 7, 8, 9 and Z are not appropriate for a given county then the files for those record types will not be included. The name of each of these files uses a modification of the above convention (TGRssccc.RTx) where "x" is the Record Type. Appendix A of the documentation provides a list of counties and their FIPS codes by state. Information on the content of each record type can be found in Chapter 6 of the TIGER/Line documentation. Information on decompressing the data files is found below under the heading "Data Compression". The files use the TIGER/Line record formats as described in the accompanying documentation. When decompressed they are fixed length ASCII with record separators (carriage return, line feed). The CD-ROM is in ISO 9660 format. Users with PCS will require Microsoft CD-ROM Extensions Version 2.0 or higher. ADDITIONAL CONTENTS OF THE CD-ROM: COUNTSss.TXT Each CD-ROM contains COUNTSss.TXT files in the subdirectory directory for each state under the TIGER directory. The COUNTSss.TXT files show record type file record counts by county for all states that are included on the compact disk. Note that all counties are listed for a given state. The layout of COUNTSss.TXT is as follows: FIPS state code 16:17 FIPS county code 20:22 Creation date 25:30 Record type 33:33 Record Count 36:43 README.TXT The document that you are presently reading. DOCUMENTATION The documentation for the TIGER/Line files is contained in the TECHDOC subdirectory. The file name is TIGER98V.PDF and is provided in the PDF format which requires the ADOBE(TM) Acrobat 3.0 Reader. We are including the installation software for both the Windows 3.1 (ar16e301.exe) and the Windows 95 (ar32e301.exe) versions of the reader. They are included in the TECHDOC/ACROREAD directory. Choose the appropriate version of this software, copy it to the hard drive of your computer and run it. It will install the ADOBE Reader software on your computer. When the installation is complete you can view the TIGER/Line documentation by running the ADOBE Reader and selecting the TIGER98V.PDF file from the "Open" menu. To get the ADOBE Reader for other computer platforms visit the ADOBE Web site for the proper software (http://www.adobe.com). Windows is a trademark of the Microsoft Corporation. ADOBE and Acrobat Reader are trademarks of Adobe Systems Inc. GARM The Census Bureau has published a Geographic Areas Reference Manual (GARM) which is available on this CD-ROM in the TEXTDOC/GARM subdirectory. This publication describes the various geographic programs at the Census Bureau and provides definitions of technical terms and a wealth of background information on the various geographic concepts used by the Census Bureau. The manual was produced in ADOBE PDF and is separated into individual chapters to provide smaller file sizes for easier access. DATA COMPRESSION The TIGER/Line data on this disk has been compressed into an archive file to save space and reduce the number of disks required for the data. If the files were not compressed it would require over 40 CD-ROM disks to hold the data needed to cover the entire United States. Use software compatible with PK-ZIP 1.93A or higher to decompress the data. Info-ZIP's software (Zip, Unzip and related utilities) are examples of packages that can be used. The Info-ZIP software is free and can be obtained as source code or executables from various bulletin boards and on line services software archive sites. There are versions for many computer platforms. One site from which this software can be downloaded is: http://www.cdrom.com/pub/infozip/UnZip.html KNOWN PROBLEMS AND ANOMALIES WITH THIS TIGER/LINE DATA SET: ADDRESS ANOMALIES IN PUERTO RICO AND QUEENS, N.Y. The TIGER/Line files contain some address range coverage for Puerto Rico. However, use of this information for geocoding purposes may be problematic and the data user should proceed with caution. These address ranges are preliminary attempts at using Puerto Rico address ranges in Census Bureau files. Due to the lack of software or resources to handle some of the more unique aspects of addressing in Puerto Rico, the address ranges were entered without the standard edits and quality checks used in other parts of the United States. Improvements in software and address standardization for Puerto Rico are expected in the future. At present, there are inconsistencies, overlaps, and duplication of address ranges. Address ranges may lack alpha character prefixes or have hyphenated prefixes. The files also lack the community names used in a four-line address that the U.S. Postal Service requires to avoid duplicate addresses. Errors in the reference files, and other factors may limit the usefulness of this product for geocoding purposes. Address range data for Queens County, NY in TIGER/Line does not show a consistent use of hyphenated and non-hyphenated addressing. The Census Bureau intends to correct this in a future version of TIGER products. CALIFORNIA RECORD TYPE C EXTRANEOUS DATA Due to some technical problems, Alpine (003) and Contra Costa (013) counties will have additional data in their Record Type C (RT C) file. The additional data consists of 1990 voting district and place entity records from adjacent counties in which they had county boundary changes with since 1990. For example, Alpine County has all of Amador County's 1990 voting district and place entity records in RT C. In addition, there may be additional counties with the same problem in the state of California or in the United States. However, the aforementioned counties are the only ones exhibiting this problem. The Census Bureau's Geography Division is in the process of fixing the problem. ROAD FEATURE ANOMALIES The Census Bureau extracts TIGER/Line files from the TIGER data base which is continually updated. During the update process for some 1998 TIGER/Line files errors caused anomalies to be introduced into some chains represented in Record Types 1 and 2. For these cases road features may appear in the 1998 TIGER/Line files unconnected to other road features (so-called floating features) or severely skewed in relation to surrounding line features of any type. Another road feature anomaly is the sporadic occurrence of road segments with a misclassified Census Feature Class Code (CFCC). The result is that complete chains for the affected road features will have segments with different CFCC values assigned erroneously. This problem could affect applications that use the CFCC values for network analysis, routing, or for assigning symbology to a feature when creating a map. We believe that these errors were introduced inadvertently during an updating operation to edit address range information on new as well as existing records. These errors will be corrected in the version of the 1999 TIGER/Line (also known as the VTDP Verification TIGER/Line) scheduled to be released in late 1999. INTERNAL POINT ANOMALIES For some polygon internal points (Record Type P) the latitude and longitude calculated for that point lies on a vertex. These occurances are limited to very small polygons. For most uses this will not be a problem, however, some GIS software applications use a higher precision in calculating the locations of features which can cause the internal point to fall slightly outside of the polygon. This in turn can cause the software to malfunction. QUESTIONS AND ADDITIONAL INFORMATION Questions regarding the Voting District Project should be directed to either John Byle or Janemary Rosenson of the Geography Division at (301)457-1128. Technical questions about the Census TIGER/Line files and future plans for this and other TIGER-related products may be directed to the Products and Services Staff of the Geography Division at (301) 457-1128 or to the e-mail address tiger@census.gov. In addition to this Cooperative Program version of TIGER/Line the Census Bureau also produces a version of TIGER/Line for public sale and a variety of related products based on TIGER data. General information about these products is available from the TIGER page on the Census Bureau's World Wide Web site (http://www.census.gov/geo/www/tiger/). This Web site also is a source of information that is of specific interest to TIGER/Line users and of general interest regarding the geographic programs at the Census Bureau. As appropriate, additional information about this product will be posted, such as ERRATA or USER NOTES.