TD 1.1: Department of Transportation (1966- )
TD 1.101: National Transportation Safety Board (1966- )
TD 1.202: Transportation Security Administration (2001-2003)
TD 2.1: Federal Highway Administration (1966- )
TD 2.101: Bureau of Public Roads (1967-1969)
TD 2.201: National Highway Safety Bureau (1966-1970)
TD 2.301: Federal Motor Carrier Safety Administration (1966- )
TD 3.1: Federal Railroad Administration (1966- )
TD 3.101: Railroad Safety Office (1966- )
TD 4.1: Federal Aviation Administration (1966- )
TD 4.101: Office of Airport Planning and Programming (1967- )
TD 4.152: Airport Safety and Standards Office
TD 4.201: Office of Aerospace Medicine (1964- )
TD 4.301: Air Traffic Organization (1967- )
TD 4.401: Flight Standards Service (1967- )
TD 4.501: Associate Administrator for Research and Acquisitions (1994- )
TD 4.601: Aircraft Development Service (1967- )
TD 4.701: Airway Facilities Service (1967- )
TD 4.801: Civil Aviation Security Service (1967-2002)
TD 4.901: Aircraft Certification Service
TD 5.1: Coast Guard (1966-2003)
TD 6.1: Saint Lawrence Seaway Development Corporation (1966- )
TD 7.1: Federal Transit Administration (1968- )
TD 8.1: National Highway Traffic Safety Administration (1970- )
TD 9.1: Pipeline and Hazardous Materials Safety Administration (1975- )
TD 10.1: Research and Special Programs Administration (1977-2005)
TD 11.1: Maritime Administration (1981- )
TD 12.1: Bureau of Transportation Statistics (1992- )
TD 13.1: Surface Transportation Board (1995- )
TD 14.2: Pipeline and Hazardous Materials Safety Administration (2004- )
