Strangely I normally use complete defensive driving technique and just let 'em pass me. If they're ahead of me it's much easier to keep an eye on them and avoid them.
Seems to work for most driving; albeit there are times that I will be more aggressive, either for fun or if I really am in a hurry, & of course there are times when you need to use speed to get out of a bad situation.
The later situations are rare, & in cases of a driver who is truly dangerous I've sometimes decided to take a five minute break. That's more than enough time for them to get a few miles away, & find whatever fate awaits them without including me in it.