The United States Department of Transportation (DOT) is a federal cabinet department of the U.S. government. The Department of Transportation was established by an act of Congress on October 15, 1966. The Department's first official day of operation was April 1, 1967. Its mission is (per the official website):
Serve the United States by ensuring a fast, safe, efficient, accessible and convenient transportation system that meets our vital national interests and enhances the quality of life of the American people, today and into the future.
Federal agencies that are part of the DOT include the National Highway Transportation Safety Administration (NHTSA), the Federal Motor Carrier Safety Administration (FMCSA), and the Federal Highway Administration (FHA), among others.