Except as prohibited by § 19.2-59, on his request or signal, any law-enforcement officer who is in uniform or displays his badge or other sign of authority may:
1. Stop any motor vehicle, trailer, or semitrailer to inspect its equipment, operation, manufacturer's serial or engine number; or
2. Stop any property-carrying motor vehicle, trailer, or semitrailer to inspect its contents or load or to obtain other necessary information.
Nothing in this section, however, shall be construed to authorize the establishment on any highway of police check-points where the only vehicles subject to inspection are motorcycles.