CFR Title 49 - Transportation (Code of Federal Regulations) is the principal set of rules andregulations issued by the Departments of Transportation and Homeland Security regarding transportation and transportation related security.
Volume 9, Parts 1200 to 1699 covers:
Chapter X – Surface Transportation Board, Department of Transportation (continued)
Chapter XI – Research and Innovative Technology Administration, Department of Transportation
Chapter XII -- Transportation Security Administration, Department of Homeland Security