Regarding joining motorways and dealing with people joining.
I agree with Dead Eye, as long as there is no one in front of you on the slip road, I always make sure im doing a good chunk more speed than the people already on the M-way, its easier to scrub 20mph off than to put it on. Plus you are more likely to find a point to safely join if you are going at a different speed than the other vehicles, passing more gaps in the traffic, and its always better to slow down, join, and match speed, than to join going slower than the flow of traffic, then try to speed up to get away from the artic up your chuff.
I never pass a blind junction (or any junction if I can help it) when im on a M-way/dual carriageway in the inside lane, I've seen too many people come dawdling down the acceleration lane, not even looking if there are any gaps until they are 50% past the point where they could have joined, then try to join doing the same speed as the artic which is trundling down the inside lane at 56mph. Ive also seen too many people stop at the end of the slip road as if the solid white line is a brick wall, much to the consternation of the other people coming down the slip road only to find a car stopped where they are just not expecting it.
People who don't seem to be able to keep a steady speed up, and keep overtaking you when you are doing the same speed.
People who hog lanes and don't pull over when they can, even when there is obviously a queue of traffic behind them.
People who pull out in front of you and make no effort to match your speed, causing you and everyone else behind you to slow down.
The people above usually don't even know they are doing anything wrong, they are completely oblivious to you behind them, and everything else which is not in their line of sight right in front of them. If they do look in their mirrors and see you there when you weren't there before, they do not think, "Where's he come from?, he wasn't there before, he must be travelling quicker than me, better get out of his way and let him bugger off", they are more likely to look see you there and think "theres a car behind me" AND THAT'S IT!!!! No further thought is dedicated to you.
I blame the demise of the public information film and people just having no thought for other road users.
I could go on for hours, but I wont (thankfully).