This has a lengthy preamble, but trust me, it's worth it. We live on a housing estate with only one access to a public highway. Said highway is currently closed in one direction to allow for some major building works. The side of the highway that is still open takes traffic going in one direction (south) but traffic wanting to head north has to take a brief (two minutes at most) detour through an adjacent estate. Going along the highway in a northerly direction, there are signs for at least five miles warning that there is a detour ahead. When you get to where the detour starts, there are huge signs telling you to turn left. It's still possible to go straight on for about a hundred yards, but all this does is give you access to the private road into our estate. And indeed, this is what the notices say - 'Detour starts here. Access ahead for estate residents only'. Plus, to reinforce this, the road to the estate has been narrowed with traffic cones. Nice and unambiguous, yes? Alas, not for some motorists. We have two specimens of moron: (1) Those who drive straight on and haven't noticed the detour signs. Both my wife and I have been stopped by confused motorists who've got on to the estate who want to know where to pick up the main highway. 'What diversion?' is the usual response. (2) Those who see the 'estate residents only' sign and think that this means that the estate residents somehow have privileged access and can get through without the detour and accordingly, they will use this shortcut as well (incidentally, there is no shortcut - we're in the same position as non-residents). Nearly every one of these is a BMW driver, curiously enough, and they are really pissed when you tell them that there is no secret way through. You might think that this would be a rare problem, but at least once a day when we've been leaving the estate or returning we've seen someone committing one of these errors, so extrapolating from this sampling, there's probably at least 40 such incidents per hour. It's now got to the stage where the police are regularly stationing a patrol car. Therefore we have a worryingly high percentage of drivers who either don't notice traffic signs or think that they can flout regulations and appropriate the rights of others.