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Liner Notes

Our Mission

To lead in developing transportation data and information of high quality and to advance their effective use in public and private transportation decisionmaking.

Our Vision

Data and information of high quality supporting every significant transportation policy decision, thus advancing the quality of life and the economic well-being of all Americans.

Description

The National Transportation Atlas Databases 2007 (NTAD2007) 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 (CD-ROMs) support research, analysis, and decisionmaking 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.

These databases do not provide explicit connections between modal networks and terminals. RITA/BTS plans to enhance future releases to provide intermodal connectivity, additional attributes, and passenger and commodity flow information.

Format: 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

Design: The NTAD2007 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 shapefiles' linkage between the attribute and spatial data.

Compilation: The data used to compile NTAD2007 was provided by our partners within the U.S. Department of Transportation (USDOT) and by other federal government agencies. These contributors are the data stewards and are ultimately responsible for the maintenance and accuracy of the data. RITA/BTS performs structured quality evaluations on the NTAD databases as they are incorporated into research and analysis projects. Further details pertaining to the NTAD2007 compilation process may be found in the metadata file associated with each dataset.

Contents

NTAD2007 is organized into a series of subdirectories, one for each feature type (point, polyline, and polygon) and one for each database. Disc 1 contains polyline features. At the top level of Disc 1, there is also a docs subdirectory containing the back cover notes and these liner notes. Also at the top level of Disc 1, there is a pdf version of RITA/BTS map Major Transportation Facilities of the United States. This map showcases the data contained in NTAD2007. Disc 2 contains point and polygon features.

Transportation networks are polyline databases. Transportation facilities are point databases. The geographic reference databases may exist as any of the three feature types: point, polyline, or polygon.

All data included on these CD-ROMs are in shapefile format. Each shapefile dataset within NTAD2007 is composed of six different files:

1. the main file (.shp), which stores the feature geometry;
2. the index file (.shx), which stores the indices of the feature geometry;
3. the dBASE file (.dbf), which stores the attribute information for the features;
4. the projection file (.prj), which stores the projection and datum information for the dataset;
5. the spatial index file (.sbx), which stores the spatial index for read-write of shapefiles; and
6. the spatial index file (.sbn), which stores the spatial index for read-write of shapefiles.

The shapefile format is a simple, non-topological format for storing the geometric location and attribute information of geographic features. For further information concerning the definition of SHAPE, consult ESRI documentation.

Metadata documentation describing source, responsible agency, file format, and any additional discussion regarding the use of a dataset is provided in the hypertext markup language (.htm) and text (.txt) files located within each database subdirectory. There is also an extensible markup language (.shp. xml) file that provides metadata viewable with ArcGIS software. Other supporting documentation may be provided in text (.txt) or Word (.doc) format.

A listing of the NTAD2007 database subdirectories, with a brief description of each, follows. Please refer to the metadata for more detailed descriptions of each dataset.

Point

airports (updated) Airports—Landing facilities in the United States—Data provided and maintained by the Federal Aviation Administration, 2007.

amtk_sta (updated) Amtrak Stations—Data provided and maintained by the Federal Railroad Administration, 2007.

atr Automatic Traffic Recorder Stations—Data provided and maintained by State Departments of Transportation and submitted to the Federal Highway Administration, 2006.

place2000 National Populated Places—Place locations from the 2000 Census Master Area Reference File–Data provided and maintained by the Bureau of the Census, 2000 with additional attribute information from Geographic Names Information System 2003.

port U.S. Army Corps of Engineers Ports—Data provided and maintained by the USACE, 2006.

terminal Intermodal Terminal Facilities—Data compiled by the Bureau of Transportation Statistics, 2003.

wim Weigh in Motion Stations— Data provided and maintained by State Departments of Transportation and submitted to the Federal Highway Administration, 2006.

Polyline

hazmat Hazardous Material Routes —Data provided and maintained by the Federal Motor Carrier Safety Administration, 2006.

hpms Highway Performance Monitoring System—Data provided and maintained by State Departments of Transportation and submitted to the Federal Highway Administration, 2006. Attributes represent calendar year 2003. Because of the size of the attribute file, the HPMS data is distribute in ZIP format. Be aware that the unzipped HPMS data is more than 600 MB.

nhpn National Highway Planning Network—Data provided and maintained by the Federal Highway Administration, 2006. (Note: A nodal shapefile called “nhpnnd” is also provided.)

railway (new) Railway Network (1:100,000 base scale)—This year FRA created a new railway database that combines the spatial accuracy of rail100k with the attribute rich rail2m to form a single more robust railway database. railway replaces rail100k and rail2m, which were distributed on previous versions of NTAD. Data provided and maintained by the Federal Railroad Administration, 2007. (Note: A nodal shapefile called “railwaynd” is also provided.)

runway (updated) Airport Runways—Data provided and maintained by the Federal Aviation Administration, 2007.

transit Fixed-Guideway Transit Facilities—Transit database including fixed guideway links and stations, 2004.

waterway U.S. Army Corps of Engineers Navigable Waterway Network—Data provided and maintained by the USACE, 2006. (Note: A nodal shapefile called “waterwaynd” is also provided.)

Polygon

boc_uza Bureau of the Census Urbanized Area Boundaries (1:100,000 base scale)—Data provided and maintained by the Bureau of the Census, 2000.

cd110 (new) The 110th Congressional Districts Boundaries (1:100,000 base scale)—Data provided and maintained by the Bureau of the Census, 2007.

county U.S. County Boundaries (1:100,000 base scale)—Data provided and maintained by the Bureau of the Census, 2000.

hydro Hydrographic Features—Data provided and maintained by the RITA/BTS, 2006. (Note: A linear shapefile called “hydrolin” is also provided.)

milbase U.S. Military Installations—Data provided by the Surface Deployment and Distribution Command - Transportation Engineering Agency, 2006.

mpo (updated) Metropolitan Planning Organization—Database of MPO planning area boundaries collected by RITA/BTS and FHWA, 2007.

msa National Metropolitan Statistical Areas (1:100,000 base scale)—Data provided and maintained by the Bureau of the Census, 2003.

naa Non Attainment Areas — Environmental Protection Agency (EPA)-defined areas of the country where “air pollution levels persistently exceed the new national ambient air quality standards,” 2006.

park National Park System Boundary Dataset—Data provided and maintained by the National Park Service, 2006.

state U.S. State Boundaries (1:100,000 base scale)—Data provided and maintained by the Bureau of the Census, 2000.

Technical Support

For assistance using these CD-ROMs or the data they contain, please contact RITA/BTS via e-mail at answers@bts.gov and refer to the NTAD2007.

For assistance with importing the data into a GIS software package, please contact technical support for the specific vendor.

User comments are critical to improving future editions of NTAD. Your feedback and corrections will be incorporated into the subsequent releases of these datasets. Please check our website (http://www. bts.gov/programs/geographic_information_services/) for any corrections or addendums to NTAD2007.

Acknowledgments

NTAD2007 is the result of cooperation throughout the U.S. Department of Transportation, the U.S. Army Corps of Engineers, the U.S. Bureau of the Census, the Environmental Protection Agency, the Surface Deployment and Distribution Command - Transportation Engineering Agency (SDDCTEA) and the National Park Service.

Most of the geographic reference datasets are products derived from the TIGER database, the TIGER /Line files, or other products created and maintained by the U.S. Bureau of the Census. We greatly appreciate these contributions.

Special thanks goes to the following individuals and organizations which contributed the data that made NTAD2007 possible: Bruce Spear of the Federal Highway Administration; Raphael Kedar, Gary Baker, and Raquel Wright of the Federal Railroad Administration; and the Federal Aviation Administration’s Aeronautical Information Services Office. We would also like to recognize the contributions of the following individuals within the Research and Innovative Technology Administration’s Bureau of Transportation Statistics who were responsible for compiling NTAD2007: Stephen Lewis, Derald Dudley, Michael Barry, Mark Bradford, and Felix Ammah-Tagoe.