Missouri Traffic Laws

Other Equipment Of Motor Vehicles Section 6.
1. When one vehicle is towing another:
1a. The connecting device shall not exceed fifteen feet.
1b. Lights shall be displayed on both vehicles when lights are required.
1c. Shall have a secondary coupling to the towing vehicle by means of a safety chain, cable, or equivalent device and
-Secondary coupling device shall not be necessary if the connecting device is connected to the towing vehicle by a center-locking ball located over or nearly over the rear axle and not supported by the rear bumper of the towing vehicle.
-Such secondary safety connecting devices shall be of sufficient strength to control the towed vehicle in the event of failure of the primary coupling device.