Rigid step cover, and running board with this cover

The covering plate (4) for the tread surface of a step, e.g. on a vehicle such as a truck, is made from a synthetic material and has fastenings that allow it to be removed and replaced, including at least one lug on the underside of the plate that goes behind the body of the step. It also has holes for fixings (18) along its front and rear edges, and its front edge has a wall (28) that extends downwards and fits against the front face of the step. Its upper surface has a series of spiked ridges (26) to give a grip.