Some interesting reactions here..........I guess it comes down to what type of person you are - someone who obeys the law, no matter whether its ill thought out, inappropriate, or illogical, or whether, like me, you take a view that you are intelligent and skilled enough ( in this case we are talking about driving) and can make your own decisions about what's safe. If I don't agree with a law about something, I don't comply, but that's just me, I am not judging anyone else. So, yes, I speed when I want to...not always, but sometimes and I always drive extremely safely, plenty of space between cars, never overtake without perfect visibility, never speed in urban ares, etc etc. I have been driving over 30 years and have a clean licence and never had a serious accident.
In relation to the question in the post, it's all about appropriate speed for the situation.......you drive at 70mph on the motorway, but if road conditions etc were bad, it would be unsafe. So blindly following the limits is not right. I ride a motorbike as well as driving a car and you need to read the roads, read the surroundings and the conditions. If the road is not busy, visibility good and you wanted to drive at say 80 or 90 mph...whats the harm? of course, if the conditions change, you adjust accordingly. Also, you should never speed in built up areas. But on the open roads, it's a different story. Plus, you have to remember, the technology and performance of modern cars, with ABS, airbags, great tyres, etc makes them and driving much safer and also the speed limits on open roads much less relevant. Look at Germany - do they have a problem there? No.......
Speed itself is not the problem, is when it is combined with the wrong conditions and a lack of skill and ability to determine what is safe. We are fed the line about safety so much, but these cameras are all about revenue raising - if they were not, then why hide them? Also, the law is designed to fit the lowest common denominator, so unfortunately, its one size fits all.
Bottom line, use your own discretion, and be prepared to deal with the result if you choose to speed and get caught. And if you do speed, then you need to be bringing your A game to the table, as a motorcyclist, I always assume the other people on the road are idiots and have not seen me. So you assume the worst may happen, be prepared and cover the brake etc..By the way, I would totally not condone a lot of the riding I see many bikers doing, I use trackdays now to get my kicks, and drive pretty sedately on the roads when on the bike.
PS, the bit about someone stepping out - do think they will be any less dead if you were doing say 60mph ( national speed limit) instead of say 70mph? or 80mph ? If someone steps out into a busy road unexpectedly, then pretty sure its going to be messy, even with everyone obeying the limits.