Amtrak
American Public Transit Association (APTA)
Community Transportation Association of America (CTAA)
Federal Highway Administration (FHWA)
Federal Railroad Administration (FRA)
Federal Transit Administration (FTA)
National Highway Traffic Safety Administration (NHTSA)
National Transit Institute (NTI)
PennDOT
Routes - A look at the lighter side of public transit
SEPTA
Southern California Transit Advocate's list of links
Transportation Research Board (TRB)
U.S. Bureau of Transportation Statistics (BTS)
U.S. Dept. of Transportation (DOT)