All this talk of better brakes etc is a poor argument since reaction time is more important - the time taken for you to realise there's a problem and do something about it.
Say it took you half a second to react to a problem, going at 70mph you'd travel approx 15 metres before you could do anything at all. At 140, that distance is 30 metres. Brakes are pretty irrelevant if you just hit something at 140 mph because you simply didn't have time to even apply the brakes.
That's why I think a crappy car at 70 is safer than a sporty car at 140 - you're more likely to have a chance to avoid collision or reduce your speed to non-fatal levels.
I remember reading that people always think they are better drivers than they actually are so comparisons to somebody like Michael Shumacher is folly - the average driver is nowhere near as capable as somebody with a) obvious natural talent b) mental and physical training c) constant practice.
People already die left right and centre on the roads and raising speed limits isn't going to reduce the toll, only increase it.
If you decide to drive faster you are far more aware and are concentrating much harder on everything around you compared to just pootling along daydreaming. You are right about reaction times resulting in taking a longer time to stop but if you are speeding you are still likely to react very fast due to the circumstances, and if you are in a high performance car you will stop before a crappy car can.
I have a friend who obeys the speed limit to a t and he is a very careful driver. He has been driving as long as me where as i often exceed the limit, yet he has had 4 crashes in 18 years and i have had none. I have not even put a scratch on a car. Im not saying im a brilliant driver but my car's of choice over the last 10 years have had over 200BHP which means 2 things: 1: they have better brakes than a standard car and 2:they take a lot more concentration to drive.
Only 3% of crashes are speed related the rest are down to driver error and lack of concentration. The fastest roads in the UK are motorways and yet they are the safest.
Im not saying get rid of speed limits, what i am saying is the modern car is far more capable and safer machine than the cars in the 60s but the law has stayed the same when the motor car has moved forward. It needs looking at especially for motorways i think lane1 shoud have a limit of 70MPH, lane 2 80MPH and lane 3 90MPH.
I also think to overtake another vehicle you have to exceed the speed limit to do it safely, the majority of head on crashes are caused because driver's have miss-judged the time it takes to overtake mainly because their cars are too slow and therefore take along time to overtake.
I have seen so many speed camera's with tyre marks in the middle of the road because some poor sod has overtaken a slower car only to be greeted with a speed camera and then they slam on the anchor's causing a dangerous situation when there should not have been one. If you are so stuck on speed limit's then all cars to pass the MOT should be fitted with a 70MPH speed limiter. Lorries all have a 55MPH limiter on them so why have we not got one for all cars? Maybe all A and B roads should have double white lines on them preventing any overtaking whatsoever.
The biggest problem for me is that the driving test is not comprehensive enough, apart from not being tested on motorways or at night learner drivers are not taught how to steer in to a skid or drive a car with a load of screaming kids in the back. Your getting driver's who just passed their test who really have no idea how to handle a car. It took me a good couple of years after i passed my test(i actually failed it 3 times) before i felt comfortable behind the wheel. My long winded explanation is that if you are not a highly competant driver you should not be behind the wheel until you are and maybe all drivers should have to pass an advanced course before being allowed on our roads, sureley that would help make britains roads safer.