Mich. Comp. Laws § 480.13a: Trailers or trailer-vehicle combinations; surge brakes equipment for intrastate operation.

Sec. 3a.

Trailers with a gross vehicle weight or gross vehicle weight rating of 15,000 pounds or less or trailer-vehicle combinations with an actual gross vehicle weight or a gross vehicle weight rating of 26,000 pounds or less may be equipped with surge brakes for intrastate operation as allowed by section 705(1)(c) of the Michigan vehicle code, 1949 PA 300, MCL 257.705.