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U.S. CENSUS BUREAU TIGER/Line 2003 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 (Census 2000 geographic areas) while others are updated and legally in effect as of the latest Boundary and Annexation Survey (BAS) (current geographic areas). The current boundaries represented in the 2003 TIGER/Line files are those reported to the Census Bureau by April 1, 2003 as being in effect as of January 1, 2003. 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. WHAT'S NEW - KEY CHANGES The 2003 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 2003 TIGER/Line files are released by county or statistically equivalent entity based on the current boundaries in effect as of January 1, 2003 as reported to the Census Bureau by April 1, 2003. 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 produces a TIGER/Line file for the Midway Islands. The 2003 TIGER/Line files include the new Record Type E which did not appear in the 2002 TIGER/Line files. Record Type E contains the geographic entity codes reflecting the boundaries of the 2002 Economic Census geographic entities. In 2002 the U.S. Census Bureau began a multi-year project, the MAF/TIGER Accuracy Improvement Project (MTAIP), to correct and update the spatial accuracy of the TIGER database. A portion of the nation's counties or statistically equivalent entities will be updated each year until all counties are completed in 2008. While MTAIP was underway before the creation of the 2003 TIGER/Line files, no counties were through the MTAIP process at the time the benchmarks used to create the 2003 TIGER/Lines were created. The 2003 TIGER/Line files for 124 counties or statistically equivalent entities contain improved street feature coordinates from pre-MTAIP coordinate improvement projects. Twenty of these counties or statistical equivalent entities with improved street feature coordinates appeared in the 2002 TIGER/Line files. The Census Bureau is including county based Federal Geographic Data Committee (FGDC) compliant metadata for the first time as part of the compressed 2003 TIGER/Line files. More information about the metadata is found below under the heading "METADATA." To avoid one of the major difficulties data users had last decade with the mixing of "current" state and county codes with decennial census tract and block numbers which are uniquely identified only by the decennial census state and county codes, the U.S. Census Bureau is continuing to provide Census 2000 codes on Record Type 1 even though the distribution unit for the post-Census 2000 TIGER/Line files is current county or statistically equivalent entity. Since some county or statistically equivalent entity boundaries have changed since Census 2000, the current boundaries may not match those used in Census 2000. Thus it is possible to find some territory that was in County A in the Census 2000 versions of the TIGER/Line files in the post-Census 2000 TIGER/Line file for County B. In counties or statistically equivalent entities that have gained territory, it is possible to have a complete chain that is a current county boundary and has the SIDE1 flag set, but has the same state and county codes on both sides of the complete chain. This occurs because a polygon that was, for example, in the Census 2000 TIGER/Line file for County A now is in the post-Census 2000 TIGER/Line file for County B. Since Record Type 1 displays the Census 2000 geography, the state and county code for County A (the county or statistically equivalent entity the lost territory) appears on this complete chain even though it currently is part of County B. The other side of this complete chain is in an adjacent TIGER/Line file and the U.S. Census Bureau appends the current state and county code of the adjacent county (County A) to this complete chain. The result is a complete chain that is a current county boundary yet has the same state and county codes on both sides of the complete chain. TIGER/LINE AND ACCOMPANYING FILES To improve the ability of data users to merge multiple counties, the Census Bureau has added 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 the 2002 version, all the data elements for the side of the record "outside" the county were 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. 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 Type U does not appear in the 2003 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. 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). METADATA County-based Federal Geographic Data Committee (FGDC) compliant metadata is included as part of each compressed TIGER/Line file. The metadata file has the name TGRssccc.met, where the "ss" is the state FIPS code and "ccc" is the county FIPS code. DATA COMPRESSION The TIGER/Line data on this disk have 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. Use software compatible with PKWARE's PKZIP(R) to decompress these files; software applications to decompress files in this format are widely available. TIGER ZERO-CELL ID (TZID) Because the 2002 TIGER/Line files were 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 with improved street feature coordinates in the 2002 TIGER/Line files 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 2003 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 2003 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. |
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