If towing something behind your vehicle, the drawbar or towing connection:

If a driver is towing something behind their vehicle, they must ensure that the drawbar or towing connection is strong enough to pull all of the towed weight safely. If the towing connection is a rope, cable, or chain, the driver should attach a square, 12-inch white flag. Unless the towed object is difficult to take apart, the towing connection should be no more than 15 feet long.