Paris Metro develops subway inspection device

The Parisian Transport Authority (RATP) combined a self-propelled vehicle with a thermal and laser scanner to inspect its subway tunnels. The Pavois, a trolley that travels on rails, supports Atlas, a scanner that produces two continuous images of the base tunnel roof surface. Run through subways after the last scheduled train finishes its route, the device allows RATP to carry out an annual inspection of the condition of its entire underground rail infrastructure.