Gosport Road and Fareham Road are notorious for dawdlers. There have been many nights where the section of road has been clear ahead apart from the car in front of me doing 30MPH, the whole stretch is 40MPH! I could overtake them then move back in but it's just not worth it usually as energy levels are reserved for brewing tea and stuff when I get indoors
Not much really annoys me, pretty much nothing I guess. Slight tediousness things aside, like if I set my cruise to 70 GPS, then the car in front will almost always without fail start to slow down which means I have to overtake them. Not an issue, but like parking far away at the supermarket with half the carpark empty only to come back to find someone has parked right next to me...