I'm likewise confused by folk that don't appear to pay any attention at all to the speed limit.
M8 last night (a crappy road with multiple speed limits) I had folk driving up my arse because I was happily tootling along (on the inside lane) at 55 in the 50 zone; when we get to the 70 bit I then pass loads of people who haven't sped up, then we get to 40 limit for roadworks, I slow to 40ish and the same folk I passed in the 70 are now behind me and apparently quite angry. Weird.
Likewise on the Queensferry Road in Edinburgh. You get folk speeding through the 30 and 40 bits, but when they finally get on to the NSL bit they just carry on at 50?
I remain convinced that this sign...

...means absolutely nothing to some people.

