As used in this part, the following definitions apply:
(1) "Department" means the department of justice.
(2) "Highway" means the entire width between the boundary lines of each publicly maintained way when any part thereof is open to public use for vehicular travel.
(3) "Motor vehicle" means a vehicle propelled by its own power and designed primarily to transport persons or property upon the highways of the state.
(4) "Occupants" means the driver and passengers in a motor vehicle.
(5) "Seatbelt" means a system using a lap belt, a shoulder belt, or other belt or combination of belts installed in a motor vehicle to restrain occupants, which system conforms to federal motor vehicle safety standards.