Oh Buckman how sweet you are to think they are for safety reasons, they are a money making scam disguised as for our safety, says I having just attended a speed 'education course', Yes I was allegedly guilty of doing 35 in a 30, caught by a hand held camera operator who was hiding in a driveway and the photographic evidence provided showed a picture of the back of my vehicle 50 yards from the hand held camera, so I was caught after I had passed the hidden operator, The course I attended had 3 classes that day of 24 pupils in each at £88 a pop.So £6336 for one day. The trainers are self employedx2 and the venue is hired, you do the maths. Now it is not in their business model to eliminate speeding drivers, in the same way that Weight Watchers don't want their members to lose weight. There are guidelines as to how and where camera vans are deployed, although I am convinced they are routinely flaunted, you try proving the guidelines weren't followed. The trainers made it very clear that once charged with speeding it is an offence that is virtully impossible to get off. I would have wasted my time trying to disprove that I was doing 35, despite there being no proof provided by the operator. The local police service know full well that the motorist will be wasting their time with any challenge and make it obvious that the pragmatic route is to pay up and do the course, mind you I did see the video on what happens if you run into a pile of cardboard boxes at 35 mph v 30 mph.Another anomaly is that there are 43 police services in Enhgland and each can choose to set it's own guidelines as to when to charge for sppeding, in some it is limit plus 10% plus 2 mph, others it is exact limit so in no way is it a level playing field