Truck tractor

(a) Every motor vehicle designed and used primarily for drawing other vehicles and not so constructed as to carry a load other than a part of the weight of the vehicle and load so drawn; and (b) For the purposes of paragraph 3 of subsection (c) of Section 14-103 of this title, the term truck-tractor shall also include oil field rig-up trucks when towing a trailer or semitrailer. Amended by Laws 1985, c. 290, § 1, operative July 1, 1985.