However, state "motor vehicle" definitions usually contain a list of exceptions of the kinds of vehicles that do not qualify—for example, vehicles that are not designed for use on public roads, vehicles propelled solely by human power, bicycles, motorized wheelchairs or other electric personal assistive mobility devices, farm tractors, implements of husbandry, motorized bicycles, mopeds, snowmobiles, all-terrain vehicles, motor scooters, and vehicles running only on rails or tracks. Each state's "motor vehicle" definition must be examined closely to see what types of vehicles qualify and what types do not. Any nonexempt vehicle that qualifies under a state statutory definition of a "motor vehicle" may be subject to that state's licensing, registration, and/or financial responsibility laws.