Middle lane hoggers, always just in their own little world completely oblivious to the world around them
People who ignore the hatched boxes you're not supposed to stop in, thanks, now I'm holding up traffic because I can't turn into where I need to go
Twats who don't understand zipper merging and try to police it by pulling out into the empty lane or straddling both lanes
People who don't indicate - especially on roundabouts, I could have gone then had I known you were turning!
People who pull out of side roads then completely fail to get up to speed quickly forcing me to brake, really you shouldn't have pulled out, but if you're going to - put your bloody foot down!
People who are scared of any slight bend in the road and are constantly braking or driving 20mph under the limit
People who think they're driving a tank, I'm constantly thinking 'come on mate you could get a bloody bus through there!'
People in BMW/Audi on the motorway who seem to think your car can just levitate out of their way. Stop flashing me, I'm already doing the limit/just over and I'm clearly overtaking, wait just a few seconds/until there's a gap for me to pull into
People who either - don't check their mirrors before pulling into the next lane on the motorway, or who can't evaluate the speed of vehicles coming up behind, or just don't care and will pull out into lane 3 to over take when I would have been past them before they even started overtaking.
Related to the last one - people who don't pull into gaps to let faster cars past, you dont need to stay in lane 3 until lane 2 is completely clear - the next vehicle is minutes away!