For purposes of this chapter, the following terms shall have the meanings indicated: the term shall be defined as:
The noncargo-carrying power unit that operates in combination with a semitrailer or trailer;
A unit as defined in Subsection A above attached to a semitrailer, trailer, or other vehicle designed to carry people or property which is towed by a motor vehicle, is constructed so that some of its weight and load rests on or is carried by a motor vehicle, and has automotive power when separated from the motor vehicle.