Dear Editor I would be the first to admit that my knowledge of electrical engineering is rather sparse. I once knew Ohm’s Law, but it has long since slipped away from my memory. However, as I understand it, if you pass a magnet over a copper coil, you get a flow of electricity. The notion that struck me whilst navigating the M50 was this: if all motor vehicles were to be fitted with magnets, and a copper cable were to be buried in the road surface, would that produce electricity? I am hoping members with expertise in this regard can tell me whether this would work (or not). Your faithfully Gerard Palmer CEng FCIBSE MIEI