Cal. Veh. Code § 630 : —CALIFORNIA VEHICLE CODEWORDS AND PHRASES DEFINED — "Trailer" defined TEXT PDF A "trailer" is a vehicle designed for carrying persons or property on its own structure and for being drawn by a motor vehicle and so constructed that no part of its weight rests upon any other vehicle. As used in Division 15 (commencing with Section 35000), "trailer" includes a semitrailer when used in conjunction with an auxiliary dolly, if the auxiliary dolly is of a type constructed to replace the function of the drawbar and the front axle or axles of a trailer. Ca. Veh. Code § 630 Amended by Stats. 1984, Ch. 542, Sec. 1.