Indiana Code Title 9. Motor Vehicles § 9-13-2-164

Sec. 164. (a) “Semitrailer”, except as provided in subsection (b), means a vehicle without motive power, designed for carrying property and for being drawn by a motor vehicle, and so constructed that some part of the weight of the semitrailer and that of the semitrailer's load rests upon or is carried by another vehicle.  The term does not include the following:

(b) “Semitrailer”, for purposes of IC 9-21, means a vehicle with or without motive power, designed for carrying persons or property and for being drawn by a motor vehicle and so constructed that some part of its weight and that of its load rests upon or is carried by another vehicle.  The term does not include a pole trailer.