Abstract: A device for stopping a wheeled vehicle which runs on a guide rail, comprises a scotch block connected to the rail, against which the front wheel of the vehicle can strike. The scotch block in this position fits a part of the outer circumference of the wheel up a certain height. The scotch block is formed by two distinct parts, namely a lower part and an upper part, the lower part being fixed rigidly to the rail and the upper part being retractable from a high position to a low position and vice-versa by rotation about an axis. Movement from the low position to the high position is controlled by an operating component situated upstream from and immediately adjacent the lower part of the scotch block, which component is actuated by a front wheel of the vehicle.