People who try to put "politeness" before the rules of the road.
This morning, as happens so many mornings, I was at the intersection out of my subdivision. The light went green. I wanted to turn left, while an oncoming car wanted to turn right. In the United States, right turn as the right of way, so I waited my turn.
The person turning right waited, too. And tried to wave me through.
I laid on the horn and said some impolite things that the other driver (fortunately) could not hear.
They turned. And then I turned. AS THE LAW SAYS IT SHOULD BE.