Vehicle classification according to Fedearal Highway Administration(FHWA)

1.Motorcycles: Any motorvehicle having a seat or saddle and no more than three wheels that touch the ground is a motorcycle. Motorcycles, motor scooters, mopeds, motor-powered or motor-assisted bicycles, and three-wheel motorcycles are in this class. Motorcycles are usually, but not necessarily, steered by handlebars.
2.Passenger Cars: Street cars, including sedans, coupes, and station wagons manufactured primarily for carrying passengers, are in this class.Passenger cars are also called street cars, automobiles, or autos.
3.Other Two-Axle, Four-Tire Single-Unit Vehicles: All two-axle, four-tire vehicles other than passenger cars make up this class. This class includes pickups, panels, vans, campers, motor homes, ambulances, hearses, carryalls, and minibuses. Other two-axle, four-tire single-unit vehicles pulling recreational or light trailers are also included in this class.
4.Buses: A motor vehicle able to carry more than ten persons is a bus.Buses are manufactured as traditional passenger-carrying vehicles with two axles and six tires. However, buses with three or more axles are also manufactured.
5.Two-Axle, Six-Tire, Single-Unit Trucks: Vehicles on a single frame including trucks, camping and recreational vehicles, motor homes with two axles, and dual rear wheels are in this class.
6.Three-Axle Single-Unit Trucks: Vehicles having a single frame including trucks, camping, recreational vehicles, and motor homes with three axles are in this class.
7.Four-or-More-Axle-Single-Unit Trucks: All trucks on a single frame with four or more axles make up this class.
8.Four-or-Fewer-Axle Single-Trailer Trucks: Vehicles with four or fewer axles consisting of two units, one of which is a tractor or straight truck power unit, are in this class.
9.Five-Axle Single-Trailer Trucks: Five-axle vehicles consisting of two units, one of which is a tractor or straight truck power unit, are in this class.
10.Six-or-More-Axle Single-Trailer Trucks: Vehicles with six or more axles consisting of two units, one of which is a tractor or straight truck power unit, are in this class.
11.Five-or-Fewer-Axle Multi-Trailer Trucks: Vehicles with five or fewer axles consisting of three or more units, one of which is a tractor or straight truck power unit, are in this class.
12.Six-Axle Multi-Trailer Trucks: Six-axle vehicles consisting of three or more units, one of which is a tractor or straight truck power unit, are in this class.
13.Seven or More Axle Multi-Trailer Trucks: Vehicles with seven or more axles consisting of three or more units, one of which is a tractor or straight truck power unit are in this class.