An inconsiderate fucktard
who upon attaining the leftmost lane on an interstate will not get out of the lane to let faster traffic pass by. Such an individual typically believes that since they are doing the speed limit or slightly over, no one else should be able to go faster since they would be breaking the law.
Bill was driving like an eighty year old woman in the left lane. He had thirty cars waiting to get by, but he would not get over because he was a Left Lane Bandit.