i ve been told by a police officer down with me, that you can do 35mph in a 30 mph zone, but if you do 36 mph in a 30mph zone the camera van will pick you up for it and you be done, he told me you can go 5mph over the speed limit but you cant go 6mph over in a 30mph or a 40mph zone, on motorways he said we leave you go 6mph over but if you do7mph or over they would be done for speeding, if its right or wrong i dont know but he works the camera van from our local station