(a) Subject to subsection (c) of this section, this section applies to:
(1) A truck that has a gross vehicle weight rating of 10,001 pounds or more; and
(2) A truck/trailer or truck tractor/semitrailer or trailer combination that has a combined gross vehicle weight rating of 10,001 pounds or more.
(b) While a vehicle subject to this section is being operated on a highway:
(1) The driver may not allow a person to occupy the area of the vehicle primarily intended to carry cargo; and
(2) A person may not occupy the area of the vehicle primarily intended to carry cargo.
(c) This section does not apply to:
(1) An attendant delegated to care for livestock;
(2) A vehicle that is controlled or operated by a farmer and is:
(i) Used to transport agricultural products, farm machinery, or farm supplies to or from a farm;
(ii) Not used in the operations of a common or contract motor carrier; and
(iii) Used within 150 miles of the farmer’s farm;
(3) A vehicle owned or operated by the U.S. Department of Defense if the vehicle is controlled or operated by:
(i) Active duty military personnel; or
(ii) A member of the military reserves or National Guard on active duty, including personnel on full-time National Guard duty and personnel on part-time training; or
(4) A vehicle traveling at a speed of not more than 25 miles per hour.