Every trailer, semitrailer, and pole trailer equipped with air or vacuum actuated brakes and every trailer, semitrailer, and pole trailer with a gross weight in excess of three thousand pounds, manufactured or assembled after July 1, 1967, shall be equipped with brakes acting on all wheels and of such character as to be applied automatically and promptly, and remain applied for at least fifteen minutes, upon breakaway from the towing vehicle. A violation of this section is a Class 2 misdemeanor.
SDCL 32-18-17