Just to clarify, the logic I've used to base my thoughts around are based on the fact that for any motorist paying attention, there are 3 causes of accidents. Changing direction without taking other roads users into consideration Changing speed without taking other roads users into consideration Driving at a rate that is inappropriate to the conditions. Safety cameras, as you corrected me that they are called, do nothing to prevent anything other than driving too fast, and actually cause road users to drive erratically - changing their speed. The same is true of Police officers - Near where I live by the Queens Drive Flyover Police "ambush" motorists on a dual carriageway that has a 30mph limit on a blind summit. It's plain obvious that they are doing this as it only started once the cuts were announced. As for your comment about cost, I live in Liverpool on the main ring road, and I'd love to see them put the speed limit up to 40. We also have some of the highest council tax in the country, so it's about time that we got value for that money. UK PLC has not been run for the people for a very long time, and the public sectors need to be pulled into line with the commercial realities. That is where I feel that the last government allowed the changes to go on unchecked for too long, but that is a completely different conversation and off topic. The methodology that is being employed currently is a prime example of the nanny state mentality, and governing by Statistics. It's going the same way that Health and safety and political correctness had gone... The current limit is impractically low for a country with 60m people in it paying such high taxes to be on the road. The changes would actually fund themselves if you think about it because the additional amount of fuel consumed by people driving less efficiently actually raises revenue! 70mph was introduced in the 60's as a result of Lotus and other car owners/manufacturers using the M1 as a racetrack. It was a nominal value that they chose back then, and times have moved on considerably since then, you only have to read a recent copy of the highway code and compare it to one from when I passed my driving test (1990's) Maybe 100mph is too fast, but you've got to ask why have a blanket speed limit, and not one that is set based on the conditions - undoubtedly it'll be due to cost, not because of safety. The reason that there are 2+ lanes on dual carriageways etc are for overtaking. If people were driving as they were taught, then the only times that we'd need to use that outside lane would be to overtake that car entering the flow of traffic. With more active policing and enforcement this could be changed, but as it is nothing will change, just the number of users being crammed onto the ash-felt at an ever slowing rate.