National Transportation Atlas Databases: 2003

The National Transportation Atlas Databases 2003 (NTAD2003) is a set of nationwide geographic databases of transportation facilities, transportation networks, and associated infrastructure. These datasets include spatial information for transportation modal networks and intermodal terminals, as well as the related attribute information for these features. Metadata documentation, as prescribed by the Federal Geographic Data Committee, is also provided for each database. The data on this twin set of compact disks (CDROMs) support research, analysis, and decision-making across all modes of transportation. They are most useful at the national level, but have major applications at regional, state, and local scales throughout the transportation community.

This product is distributed in shapefile format. The shapefile is an open format created by the Environmental Systems Research Institute (ESRI). You can find additional information about the format at: www.esri.com/library/whitepapers/pdfs/shapefile.pdf

The NTAD2003 databases are designed for use within a geographic information system (GIS); however, the attribute data for each dataset can be accessed in any database, spreadsheet, or other software package. This information is stored in dBASE format. Because of spreadsheet limitations, many of the larger dBASE files will not open correctly with spreadsheet software. It is important to note that users who manipulate attribute data outside of their GIS may alter the shapfiles' linkage between the attribute and spatial data.