Being a high-testosterone 21 year old, I get pissed daily in traffic. Humans are territorial. But I don't use that as an excuse to take the Low Road. I am a very sane driver, and in fact I usually refuse to speed up even if someone seems to be getting furious at me for it. As a matter of fact, if anyone gets pissed at me it's likely because I'm driving too sanely. If they want to pull into the parking lot on my turf and assault me, they'll get what they deserve if the situation calls for defensive action, but otherwise I let them be. It's not too hard to understand. You should count yourself lucky that you and he are OK, and perhaps chalk it up as a lesson learned. You or he both could be hurt, maimed, dead, or in jail. Why not read Massad Ayoob's "In the Gravest Extreme," which covers these situations very well? You can get it from www.abebooks.com for cheap.