DOT employs almost 60,000 people across the country, in the Office of the Secretary of Transportation (OST) and through ten operating administrations and bureaus, each with its own management and organizational structure:

Federal Aviation Administration
Federal Highway Administration
Federal Motor Carrier Safety
Administration
Federal Railroad Administration
Federal Transit Administration
Maritime Administration
National Highway Traffic Safety Administration
Research and Special Programs Administration
St. Lawrence Seaway Development Corporation
Bureau of Transportation Statistics

The Office of the Secretary of Transportation provides overall leadership and management direction, administers aviation economic programs, and provides administrative support. The Office of Inspector General (OIG) and the Surface Transportation Board (STB), while formally a part of DOT, are decisionally independent by law and are not part of this plan.