Abstract: A pair of wheel safety chocks for blocking the rear wheels of a vehicle having a boat trailer or the like in tow, the safety chocks being connected together by a rope which, in use, is positioned so that it passes over the trailer hitch and between it and the vehicle bumper. So positioned, the rope is long enough to allow the chocks to block both rear wheels simultaneously. Moreover, without anyone repositioning either the chocks or the rope, the rope interacts with the vehicle bumper, as the vehicle is being driven forward, releasing the safety chocks and pulling them out of the path of the wheels of the oncoming trailer.