As used in this chapter, the term:

(.1) "Agricultural field use vehicle" means a commercial truck designed specifically for field applications of fertilizers, poultry litter, and crop protection chemicals which is owned and operated by a farmer or business engaged in the sale and application of fertilizers, poultry litter, and crop protection chemicals and is operated primarily off the highway.

(.2) "Commissioner" means the commissioner of motor vehicle safety.

(1) "Farm truck" or "farm trailer" means a truck or trailer for which the owner submits a sworn statement as a part of the registration application to the effect that the vehicle is used primarily on and is domiciled upon a farm primarily for the carriage of unprocessed products of the farm.

(2) "Farm vehicle" means a vehicle or combination of vehicles owned by a farmer or rancher, which are operated over public highways and used exclusively to transport unprocessed agricultural or livestock products raised, owned, and grown by the owner of the vehicle to market or a place of storage; and shall include the transportation by the farmer or rancher of any equipment, supplies, or products purchased by that farmer or rancher for his own use and used in the farming or ranching operation or used by a farmer or rancher partly in transporting agricultural products or livestock from the farm or ranch of another farmer or rancher that were originally grown or raised on that farm or ranch or when used partly in transporting agricultural supplies, equipment, materials, or livestock to the farm or ranch of another farmer or rancher for use or consumption on that farm or ranch but not transported for hire.

(3) "Motor bus" means any passenger-carrying motor vehicle operated for hire and having a passenger seating capacity of eight or more persons exclusive of the driver.

(4) "Owner declared gross vehicle weight" means the empty weight of the truck or truck-trailer fully equipped and fueled and ready for operation on the road and, in the case of combinations, means the weight when ready for operation on the road of the heaviest trailer or semitrailer with which the power unit will be placed in combination, plus the heaviest load which will be carried within the licensed period.

(5) "Private truck" or "private trailer" means a truck or trailer other than a farm truck, a farm trailer, farm vehicle, or a truck or trailer operated for hire by a common or contract carrier.

(6) "Trailer" means any vehicle operated over the public roads of this state without motive power when the vehicle is designed for carrying persons or property, either partially or wholly, on its own structure and is designed for being drawn by a self-propelled vehicle.