Look who’s breaking the speed limit!

I stood with my back to the traffic and clicked away at the speed-activated sign whenever I heard a vehicle approaching. Immediately there was white van man, then blue van man, both breaking the limit, then four cars, all going less than 30 mph, and then this offender… Chingford Road E17. A residential street with a sixth form college. This police car did not have its blue light flashing and was not sounding a siren.