| Volume | Chapter | Parts | Regulatory Entity |
| 1 | | | Subtitle A--Office of the Secretary of Transportation |
| 2 | I | | Pipeline and Hazardous Materials Safety Administration, Department of Transportation |
| 3 | | | Pipeline and Hazardous Materials Safety Administration, Department of Transportation |
| 4 | II | | Federal Railroad Administration, Department of Transportation |
| 5 | III | | Federal Motor Carrier Safety Administration, Department of Transportation |
| 6 | IV | | United States Coast Guard, Department of Homeland Security |
| V | | National Highway Traffic Safety Administration, Department of Transportation |
| 7 | | | National Highway Traffic Safety Administration, Department of Transportation |
| VI | 600-699 | Federal Transit Administration, Department of Transportation |
| VII | | National Railroad Passenger Corporation |
| VIII | | National Transportation Safety Board |
| 8 | X | | Surface Transportation Board, Department of Transportation |
| 9 | | | Surface Transportation Board, Department of Transportation |
| XI | 1400-1499 | Research and Innovative Technology Administration, Department of Transportation |
| XII | | Transportation Security Administration, Department of Homeland Security |