All such trailers as described in Section 32-9-26 shall be equipped with red reflectors to adequately illuminate the rear of such trailer by placing at least two on the rear and one at each side. No such trailer shall be in excess of 10 feet in width, except that such trailer shall not exceed 102 inches in width when operated or moved on the Interstate Highway System, and no such trailer, drawbar, or other connection, including the vehicle towing such trailer, shall be in excess of overall length of 76 feet. Overhang of round bales of hay on such trailer shall not exceed one foot per side except that the width of the trailer including overhang shall not exceed 102 inches when operated or moved on the Interstate Highway System. At no time shall there be more than one loaded trailer towed by any vehicle; provided, that two empty farm wagons or trailers with two or more wheels may be towed in tandem when the overall length of the towing vehicle and its tow does not exceed 76 feet altogether.