Department of Transportation (DOT)
federal executive division responsible for programs and policies relating to transportation. Besides the Federal Aviation Administration (q.v.) and the National Highway Traffic Safety Administration (q.v.), it controls the Federal Highway Administration (FHWA), which plans, develops, and oversees construction of interstate highways; the Federal Railroad Administration (FRA), which issues and enforces rail safety regulations and administers railroad financial assistance programs; the Federal Transit Administration (FTA), which manages mass transit development and improvement programs; the Maritime Administration (MARAD), which supervises the U.S. merchant marine; and various specialized regulatory, research, and development agencies, including offices for hazardous materials transportation and pipeline safety.