Decision Making Information: TIGER/Line

Census 2000 & Updates
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TIGER/Line 2006
(SE released 3/07)

Accessing and Using TIGER/Line Resources

Update 3/31/08. There have been important new developments affecting TIGER/Line files. The legacy TIGER/Line files are being replaced with TIGER/Line shapefiles. See the April 2008 DMINews for a brief description of how you can access and use TIGER/Line shapefiles.

Role and Scope of TIGER/Line Files. TIGER/Line files are ASCII files containing data that can be used to represent different types of point, line, and polygon geography covering the U.S. earth surface. TIGER/Line files are created from the Census Bureau's TIGER (Topologically Integrated Geographic Encoding and Referencing) database of selected geographic and cartographic information. TIGER is used by 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 available for public use and are typically used to provide the digital map base for GIS (Geographic Information System) and mapping applications.

TIGER/Line files are neither maps nor images. Maps may be created using TIGER/Line files using GIS or mapping software like CommunityViewer and TLFGeocoder. The Census Bureau does not provide software that supports use of the TIGER/Line files nor assistance in how to use these data in specific applications. Contact Proximity with questions or special needs that you might have using TIGER/Line files.

Washington, DC View Based on TIGER/Line

Importance of TIGER. Visual analysis made possible by maps is essential to effective decision-making. Development of underlying data often depends on the ability to relate data organized by one type of geography to data organized for another type of geography. The Census Bureau TIGER/Line (Topologically Integrated Geographic Encoding and Referencing) files play an indispensable role in meeting these needs. They provide the underlying vector-oriented geographic data used in most U.S. mapping and GIS applications. This section reviews access to and use of the TIGER/Line, and related derivative products and files, in the context of decision making information solutions.

Vintages. In recent years, updated TIGER/Line files have released twice a year. The second edition TIGER/Line 2006 files were released in March 2007. See TIGER/Line 2006 for more information on this version. While the most current version might be the "best" version in terms of cartographic accuracy (e.g., street coverage and related attributes), different vintages carry different geographic codes.

The Census Bureau has announced that the second edition 2006 TIGER/Line files will be the last of the TIGER/Line files to be released. Starting in the fall of 2007, the Census Bureau will replace TIGER/Line files with shapefiles and new geographic products. This Web page will provide updates as this transition occurs.

Access. TIGER/Line files may be accessed via the Census Bureau html or ftp pages. The TIGER/Line files are provided in ASCII text format only. The files are organized in county units. Users must convert/translate the files into a format used by specific software.

Viewing TIGER/Line Files as Maps. Use the Proximity CommunityViewer to open and display the raw TIGER/Line data -- without conversion. The graphic presented above shows a section of the Washington, DC (Mall area, Ellipse, Capitol complex, Union Station, Tidal Basin) TIGER/Line displayed by directly opening the ASCII data file with the CommunityViewer software.

Using Derived Files. Shapefiles may be developed from the TIGER/Line files and are one of the most widely used TIGER/Line derived files. Proximity provides access to TIGER/Line derived shapefiles that relate to different vintages. See TIGER/Line mapfiles for additional information.

Integrating Subject Matter Data. TIGER/Line files do not contain any demographic or other subject matter data. Integrating subject matter data can be one of the most significant challenges to using the TIGER/Line files. The Proximity CommunityViewer software can be used to integrate multi-sourced subject matter into TIGER/Line derived shapefiles.