Boston Metropolitan Planning Organization (MPO)

    The regional group responsible for carrying out the Federally mandated regional transportation planning process. The Boston MPO has links to traffic count data and contacts for some other transportation related data for the Boston metropolitan region, as well as research links. Note: for any metropolitan region, the region’s MPO is a good place to start looking for transportation data at the regiona/urban level.

Bureau of Transportation Statistics – National Transportation Atlas Database

    Download a variety of transportation infrastructure data in GIS format.

Bureau of Transportation Statistics

    The BTS has numerous tabular data sets, mostly by state, regarding all aspects of transportation in the US. 

Federal Highway Administration (US) – GIS Data

    A good list of transportation GIS data sources.

Transportation Research Bureau

    Census Data for Transportation Planning.