While driving down the road, what is something the other drivers do that annoys you?

I was headed to work today and encountered quite a few things. I got behind someone who was in the passing lane and going the same speed as the guy in the slower lane. A little closer to my destination I got behind a woman who was driving fifteen mph under the speed limit because she was more focused on her telephone conversation than where she was going. So, just wondering what some common peeves are while on the road.