What makes you upset the most, that happens when you are driving?

people that cut in front of you with no turn signal

people that see you coming, pull out in front of you and then drive slow

people behind you that tailgate and/or beep at you for going slow when it is the car in front of you, not you, who is going slow.

people that do not merge till the last second and then expect you to let them in when they had 2 miles to get over.

people that drive slower than the speed limit in the passing lane

that person you passed 2 miles back who was texting, singing, dancing, fixing their makup, eating etc who does not notice you are stopped at a redlight and is about to plow into you from behind at 50mph...of course when they do see at the last minute and slam on their brakes, only barely missing you, they get attitude and start making gestures and yelling.

when people fly past me on the highway just to putt along in front of me 10 miles below the speed limit . +++

People who will not use their turn singals. It's so simple to do, and lets other drivers know that something is about to happen and to be ready for it.

They seem to not know the difference between the GAS and the BRAKE! And I HATE it when the ride the damn break! SINCE THEY ARE ALREADY GOING UNDER THE SPEED LIMIT!!
ROFL! Fun question!!! +5 Mr.Cool!!!

People who are talking on cell phones and cease to drive in a normal, non-erratic manner.

People getting in front of me and not giving me time to stop,resulting in an accident.

Seeing people talking on their cellphones and not paying attention the to road.