My pet peeve was not listed: Jerks who can't/won't politely merge into traffic. When a lane is closing down or when traffic backs up at an exit, these jerks go straight to the FRONT of the line and expect to be let in. Instead of waiting their turn at the back like everyone else does. I have a cardboard sign in my car that says "Cutting in line is juvenile!". I flash it when one of these idiots wants me to let them in near the front of the line.