Abstract: A traffic cone storage unit is movably mounted on a rear portion of a motor vehicle to store traffic cones thereon. The unit includes a mounting frame attached to the undersurface of a motor vehicle adjacent to the rear of that vehicle and a stanchion pivotally mounted on that mounting frame to move between a first orientation that is upright with respect to a surface on which the motor vehicle is resting and a second orientation that is horizontal with respect to the surface on which the motor vehicle is resting. Traffic cones are stored on the stanchion when it is in the first orientation and the stanchion is out of the way when it is in the second orientation so that access can be made to the interior of the motor vehicle even when the traffic cone storage unit is in place on the motor vehicle. A chain or like tether element can be used to attach the top of the stanchion to the motor vehicle to further ensure stability thereof.