36 CFR 4.11 - Load, weight and size limits.
(a) Vehicle load, weight and size limits established by State law apply to a vehicle operated on a park road. However, the superintendent may designate more restrictive limits when appropriate for traffic safety or protection of the road surface. The superintendent may require a permit and establish conditions for the operation of a vehicle exceeding designated limits.
(b) The following are prohibited:
(1) Operating a vehicle that exceeds a load, weight or size limit designated by the superintendent.
(2) Failing to obtain a permit when required.
(3) Violating a term or condition of a permit.
(4) Operating a motor vehicle with an auxiliary detachable side mirror that extends more than 10 inches beyond the side fender line except when the motor vehicle is towing a second vehicle.
(c) Violating a term or condition of a permit may also result in the suspension or revocation of the permit by the superintendent.