Maryland Transportation Section 21-1107

      (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.