(a) No vehicle will be permitted to enter or operate within the parkway system with any article of any kind on the outside of the vehicle, unless such article is carried in or upon a rack designed for that purpose.

(b) The maximum projection of both the article and rack above the roof of the vehicle shall not exceed 30 inches.

(c) The overall height of the vehicle, including article and rack shall not exceed 10 feet.

(d) The article and/or rack shall not project beyond the front and/or rear of the permanent equipment of the vehicle more than a total of two feet and in no case shall project beyond the sides of the vehicle.