Abstract: A motor driven vehicle is described which has a control handle grasped by the operator, the handle having an inner portion connected to the vehicle and a free end portion. The speed is controlled in accordance with the position of the free end of the handle by a novel device which includes a rheostat connected to the drive motor and a rack and pinion mechanism connected to the rheostat. The drive motor is a direct current electrical motor and the rheostat has a resistance portion corresponding to and effecting a braking action on the vehicle through the motor. The novel clutch comprises an inner hub and an outer hub, and one of the inner and outer hubs has a serrated surface and the outer hub carries a plurality of needles extending toward the serrated surface the needles being canted in a given direction so that rotary motion can be transmitted in a predetermined direction between the hubs whereas for the opposite direction the hubs are substantially free-wheeling.