Without doubt driving at 57 in a 30 is far more dangerous than at 35 and anybody who does not see that is a fool. If you were to walk out in front of someone at 30 they will be able to stop in far shorter distance than someone at 57, therefore in a lot of cases the guy traveling at 30 will be able stop and not hit you, whilst the guy at 57 will still be doing 30 when you are hit. Speeding is not black and white as we all know that if you drove though a town centre at 29mph within the speed limit with your eyes closed you will kill someone within seconds. You mention that doing 35 in a 30 or 75 in a 70 is still putting people at risk, correct, but so is doing 20 in a 30, there is no speed of any kind without risk. It is all about reducing that risk. The risk of traveling at 57 compared to 30 is significantly higher. As above I stated that I do speed, everybody does, but there is a huge difference between slightly speeding in the right circumstances and doing nearly double the limit is a residential area. My personal view is that Motorway limits should be increased depending on conditions, so am not part of the anti-speed brigade, just someone who would like to live a little longer.