in any argument, it takes two to make it happen. stepping back from a situation will often diffuse it before it gets out of hand.
I've often had moments that make me want to get out of my cars and beat the living _____ out of the idiot who pissed me off. But i always keep from doing it coz I remember that you never know who or what your facing when you do so. The tabloids always have a story about someone accosting another driver and getting shot or stabbed.
It's not worth it. Making him or her realize their stupidity is not worth the risk of escalating a trivial issue to a life-threatening one.