People who refuse to change lanes to allow you to enter the highway when there's not another vehicle anywhere near.
People who don't understand the concept of a turn signal.
People who cannot maintain a constant speed on the highway. I know not everyone has cruise control, but learning to maintain a constant speed should be mandatory for getting your license.[/QUOTE]
Happens to me all the time...
I do use cruise control and will pass someone generally going uphill and then sure enough they're passing me going back down. Same thing...over and over. I don't get it...