Firstly of course I teach my children proper road sense.
Secondly, well we agree on built up areas so lets leave that one. As for motorway speeds; true they did not have speed restrictions at one point. Well done, there were far fewer cars then too and they had slower top speeds. / queue german motorway responses...
"so don't try to pretend that it is always automatically unsafe to drive over the limit if you have had proper training."
The quote above interest me. Its what I hear a lot of in one of my lines of work (which has a lot to do with this subject). Trained police are indeed permitted to travel above the speed limit. With that exception all others are not. Plain and simple dont speed it's law. Deal with it.
Oh and on that note. It's people who claim that they know what they are doing so they can speed that put everyone in danger. Do you really expect the police and courts to accept that and say "Yeah you sound like you know what you are doing so you can go above the speed limit, all others can't though". EVERYONE (with the exception of my late grandad!) thinks they are capable of speeds over than 70 and that they know what they are doing.
Plenty of people think they are okay with Class A drugs too. Should we let those that seem okay to take them?
Drive at 70 and relax. It's not a slow speed, you will get to your destination and you may even live longer.
/ I sound like I am 80 in this post and I realise that. I'm actually 30 FYI.