My number one irritation is close to numbers 3 and 4 - speeding up in an on ramp that leads to an off ramp into a long line of backed-up cars, just so you can go 71 instead of 70. Just merge already and then get left to pass!
my biggest pet peeve is when you approach a red light and there are two lanes of traffic and once the light turns green then the idiot at the front of the line turns on the directional to take a left so everybody has to wait to go around him or they cut off the people in the right lane
My # 1 - People that have no clue HOW to merge and get p*ssed when I don't move over when I have no space to make room for them. That or when I'm forced to brake because they just assume that traffic will move out of their way.
I'm sure she's a bad driver but cell phones just make bad drivers worse. I looked her right in the eye (we were that close) and she was clearly completely absorbed in her phone call and totally unaware of her surroundings. I was an agnostic on the cell phone issue until that happened to me. Now, I've joined the side of big government and limiting freedom (in this anyway).