Data.gov
The Main data portal for the U. S. Government. Here you will find data, tools, and resources to conduct research, develop web and mobile applications, design data visualizations, and more.
Department of Transportation Data Sets
An Index of all data produced by the Department of Transportation
National Transit Database (NTD)
Primary source of a broad range of information and statistics on the transit system nationwide.
Bureau of Transportation Statistics
US Department of Transportation medium of reporting statistics on all forms of transportation.
National Household Travel Survey
Conducted by the Federal Highway Administration (FHWA), the NHTS is the authoritative source on the travel behavior of the American public. It is the only source of national data that allows one to analyze trends in personal and household travel. It includes daily non-commercial travel by all modes, including characteristics of the people traveling, their household, and their vehicles.
Statistical Abstracts of the United States
The Statistical Abstract of the United States, published since 1878, is the authoritative and comprehensive summary of statistics on the social, political, and economic organization of the United States.
TranStats
Unique database, provides statistical data for transportation research.
Maryland State GIS Data
Maryland State numeric data
A source for GTFS data for Maryland and other areas.