"Sensors have been placed just below the surface of the road under half a dozen parking spaces. The high-tech probes recognize changes in the surrounding magnetic field. That allows them to detect whether a parking spot is occupied or vacant. They can also recognize whether the vehicle in the space is a car or a truck, from their distinctive magnetic profiles, and can even detect when a garbage bin is occupying the parking spot. 'This technology comes from space travel,' explains Patrick Givanovitch, head of the Toulouse start-up Lyberta, which, together with the French space agency CNES, has developed the sensors and got them ready for series production."