49 C.F.R. § 397.3 State and local laws, ordinances, and regulations.
Title 49 - Transportation
Every motor vehicle containing hazardous materials must be driven and parked in compliance with the laws, ordinances, and regulations of the jurisdiction in which it is being operated, unless they are at variance with specific regulations of the Department of Transportation which are applicable to the operation of that vehicle and which impose a more stringent obligation or restraint.
Title 49: Transportation
PART 397—TRANSPORTATION OF HAZARDOUS MATERIALS; DRIVING AND PARKING RULES
Subpart A—General
§ 397.3 State and local laws, ordinances, and regulations.