Are we talking 2-lane highway here? If so that changes things. I have only had a few unpleasant experiences with extreme tailgaters. For the most part, I stay in the right of three lanes, and everyone else goes about their merry business wasting fuel.
I must say that it does scare me when someone
gets right on my ass, not because of the risk of collision so much as the risk of them being some crazy who is going to beat or shoot me when the vehicles eventually stop.