Iowa Code Title VIII. Transportation [Chs. 306-330B] § 321.310. Towing four-wheeled trailers

1. A motor vehicle shall not tow a four-wheeled trailer with a steering axle, or more than one trailer or semitrailer, or both in combination. However, this section does not apply to a motor home, motorsports recreational vehicle, multipurpose vehicle, motor truck, truck tractor or road tractor nor to a farm tractor towing a four-wheeled trailer, nor to a farm tractor or motor vehicle towing implements of husbandry, nor to a wagon box trailer used by a farmer in transporting produce, farm products, or supplies hauled to and from market.

2. Any four-wheeled trailer towed by a truck tractor or road tractor shall be registered under the semitrailer provisions of section 321.123; provided that the provisions of this subsection shall not apply to motor vehicles drawing wagon box trailers used by a farmer in transporting produce, farm products, or supplies hauled to and from market, or to a four-wheeled trailer towed by a motorsports recreational vehicle.