JANUARY 2003 U.S. CENSUS BUREAU TIGER/Line 2002 Census TIGER(R) and TIGER/Line(R) are registered trademarks of the U.S. Census Bureau. ZCTA(TM) is a trademark of the U.S. Census Bureau. Windows is a registered trademark of the Microsoft Corporation. ADOBE, Acrobat, and Acrobat Reader are registered trademarks of Adobe Systems Inc. ZIP Code and ZIP+4 are trademarks of the U.S. Postal Service. Some legal boundaries and names are those reported to the U.S. Census Bureau to be legally in effect on January 1, 2000 while others are updated and legally in effect as of the latest Boundary and Annexation Survey (BAS). The boundaries represented in the 2002 TIGER/Line files are those reported to the Census Bureau by April 1, 2002 as being in effect as of January 1, 2002. The boundary information in the TIGER/Line files for both legal and statistical entities are for Census Bureau statistical data collection and tabulation purposes only; their depiction and designation for statistical purposes does not constitute a determination of jurisdictional authority or rights of ownership or entitlement. WHAT ARE TIGER/LINE FILES The TIGER/Line files were created from the Census Bureau's TIGER (Topologically Integrated Geographic Encoding and Referencing) database 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 and economic censuses 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. The Census Bureau cannot provide help in how to use this data with specific software packages. The TIGER/Line files are provided in ASCII text format only. Users are responsible for converting or translating the files into a format used by their specific software package. For information on how to use the TIGER/Line data with a specific software package one should contact the company that produced the software. 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. ACCESSING TIGER/LINE FILES The TIGER/Line files are distributed on CD-ROM and on the Census Bureau's Internet site (www.census.gov). This README.TXT file references both the disc and Internet distribution methods. For those downloading the TIGER/Line files from the Internet, unless otherwise noted, you can find the supplementary files mentioned below through links from the TIGER/Line download page. WHAT'S NEW - KEY CHANGES The 2002 TIGER/Line files include files for all counties and statistically equivalent entities in the United States as well as files for Puerto Rico and the Island Areas. The 2002 TIGER/Line files are released by county or statistically equivalent entity based on the current boundaries in effect as of January 1, 2002 as reported to the Census Bureau by April 1, 2002. Since Census 2000 there have been changes in the universe of counties or statistically equivalent entities. In Colorado, Broomfield County was created from parts of Adams, Boulder, Jefferson, and Weld Counties. This change has resulted in the creation of a separate TIGER/Line file for Broomfield County, Colorado. In Virginia, the independent city of Clifton Forge changed its status to become Clifton Forge town and is now part of Alleghany County, Virginia; it appears in the Alleghany County, Virginia TIGER/Line file. Beginning with the 2002 TIGER/Line files, the Census Bureau no longer will produce a TIGER/Line file for the Midway Islands. The 108th Congressional Districts do not appear in the 2002 TIGER/Line files. The Census Bureau still was in the process of collecting this information from the states at the time of the creation of the 2002 TIGER/Line files. The 2002 TIGER/Line files contain few, if any, updates to street features or address ranges from the Census 2000 versions of the TIGER/Line files. Some additional features may have been added in the 20 counties where the Census Bureau improved the street feature coordinates. In a few instances some new features may appear, and address ranges could have been added or updated, to resolve challenges as part of the Census 2000 Count Question Resolution (CQR) Program. As part of a research project to upgrade the positional accuracy of TIGER data, the Census Bureau improved the street feature coordinates in the following counties: Kent, New Castle, and Sussex Counties in Delaware; Seminole County in Florida; Cecil, Somerset and Talbot Counties in Maryland; Baltimore City in Maryland; Auglaize, Crawford, Defiance, Delaware, Fulton, Henry, Miami, Putnam, Richland, Van Wert, and Williams Counties in Ohio; and Hughes County in South Dakota. The Census Bureau has made major changes to the structure, field definitions, and contents for the 2002 TIGER/Line files. New record types have been added, two record types were deleted, and several record types were expanded and substantially revised. The Census Bureau has removed the 1990 geography from the 2002 TIGER/Line files replacing it with current geography. Also new for the 2002 TIGER/Line files is a permanent zero-cell (or node) identification number (TZID) for each node. To improve the ability of data users to merge multiple counties, the Census Bureau is adding the state and county codes to those Record Type 1 records for the adjacent county (these are the Record Type 1 records that have the single-sided segment flag set, and until this version, all the data elements for the side of the record "outside" the county have been blank). The Census Bureau also is making the TLIDs and TZIDs for these records the same. Thus the county boundary segments and zero-cells in adjacent counties will now have the same TLID and TZID. TIGER/LINE AND ACCOMPANYING FILES The Census 2000 TIGER/Line files contain digital cartographic data and are accompanied by documentation and related files. These files are distributed as a disc-on-demand CD-ROM product and on the Census Bureau's Internet site (www.census.gov). On the Internet site (start with the "TIGER" link from the home page) there are links to the directory/folder for each state where the individual files are stored. Other links lead one to the accompanying files. On the CD-ROM the TIGER/Line data is stored in the TIGER directory in subdirectories by 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 (or statistically equivalent entity) is stored in a single compressed file that, when decompressed, results in up to 19 separate files representing each of the TIGER/Line record types that exist for that county. Some counties did not require all of the 19 record types and therefore will have less than 19 files. If the types of data contained in record types 4, 6, 7, 8, B and Z are not appropriate for a given county then the files for those record types will NOT be included. New Record Types E and U do not appear in the 2002 TIGER/Line files. 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 TIGER/line documentation provides a list of counties and their FIPS codes by state. The data in these files is in a standard ASCII format. The Census Bureau does NOT release the TIGER/Line data or an extract of the internal Census TIGER database in vendor-specific GIS/mapping software formats. 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). ADDITIONAL FILES: COUNTSss.TXT Each CD-ROM contains COUNTSss.TXT files in the subdirectory for each state under the TIGER directory of the disc. If you are downloading from the Census Internet site they can be found in the appropriate state folder. The file name will have the appropriate state FIPS code in place of "ss" in the file name. The COUNTSss.TXT files show the counts for the number of records for each record type by county for all states that are included on the CD-ROM. 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 An important aspect of the COUNTSss.TXT file is the "Creation Date" information for these files. This date is the date the TIGER/Line file was created from a benchmark of the TIGER database. The process of creating TIGER/Line files involves extracting the appropriate data from various internal data sets to create what we term a TIGER/Line benchmark. Essentially this benchmark is a snapshot in time of our TIGER databases which are constantly being updated. From this benchmark we create the TIGER/Line files for use in our operations. Depending on the nature of the operation for which the files are being created, this process can proceed over several months as the sets of files for individual states are created. The VERSION CODE field in TIGER/Line identifies the benchmark used and one can determine the vintage of the file from the information in this field (see page 2-1 of the TIGER/Line documentation). However, infrequently errors are found in the benchmark or in the software that produces the TIGER/Line files. Corrections are made to the benchmark file and then a new TIGER/Line is created from the benchmark. In these situations the VERSION CODE for the original and corrected files would be the same but the "Creation Date" information in the COUNTSss.TXT file would reflect the different vintages. README.TXT The document that you are presently reading. DOCUMENTATION The documentation for the TIGER/Line files is contained in the TECHDOC subdirectory of the CD-ROM. The file name is TGR2002.pdf and is provided in the PDF format which requires the ADOBE Acrobat Reader (version 3.0 or higher). We are including the installation software for the ar505enu.exe version (5.05) of the reader in the TECHDOC/ACROREAD CD-ROM directory. If you have a version of Acrobat Reader more current than version 5.05, do not install the version of Acrobat Reader contained on the 2002 TIGER/Line CD-ROM. Included here are ADOBE's instructions for the installation of the Reader software: "Copy this software to the hard drive of your computer and run it. It will install the version 5.05 of the ADOBE Reader software on your computer. If there is a failure at any point during the installation of Acrobat Reader, the installer performs a complete uninstall. For this reason, it is important not to close the installer application by clicking its close box in the upper right corner of the background window after clicking the "Thank You" dialog box that appears at the end of the installation. If you wait for a second or two, the installer will automatically close the background windows after the installation is complete." When the installation is complete you can view the TIGER/Line documentation by running the ADOBE Reader and selecting the TGR2002.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). METADATA Federal Geographic Data Committee (FGDC) compliant metadata is included on the CD-ROM in the TIGER subdirectory. It is also available from the Census Internet download site. 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 and to facilitate downloading from the Internet. 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. They are compressed into the widely used zip format. Software applications to decompress files in this format are widely available. KNOWN PROBLEMS AND ANOMALIES WITH THIS TIGER/LINE DATA SET: TIGER ZERO-CELL ID (TZID) Because the 2002 TIGER/Line files are the first version of the TIGER/Line files to contain the permanent zero-cell identification number (TZID), we expect there to be some possible differences between the TZIDs in the 2002 and the 2003 TIGER/Line files. The Census Bureau expects the TZIDs to be stable in the 2003 and later versions of the TIGER/Line files. The differences will mainly appear in the 20 counties listed in the What's New - Key Changes section of this document where the Census Bureau improved the street feature coordinates and possibly their adjacent counties. RANGE OF TIGER/LINE IDENTIFICATION NUMBERS (TLIDS) IN RECORD TYPE R Record Type H contains the range of unique complete chain record numbers assigned to a census file. In counties with changes to their county boundaries after January 1, 2000, the complete range of TLIDs within the current county boundary do not appear in Record Type R of the 2002 TIGER/Line file for that county. Users will need to reference Record Type R from the adjoining county to identify the potential range of unique complete chain record numbers. ADDRESS ANOMALIES IN PUERTO RICO 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. ROAD FEATURE ANOMALIES The Census Bureau extracts TIGER/Line files from the TIGER database which is continually updated. During the clerical update process for some Census 2000 operations 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 2002 TIGER/Line files unconnected to other road features (so-called floating features) or severely skewed in relation to surrounding line features of any type. We correct these errors as we find them, however, it is likely that some still exist. 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. We are continuing to correct these as they are discovered. QUESTIONS AND ADDITIONAL INFORMATION Questions about the Census TIGER/Line files and future plans for this and other TIGER-related products may be directed to the Geographic Products Management Branch of the Geography Division at (301) 763-1128 or to the e-mail address tiger@census.gov. General information about TIGER-related 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 other 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.