I have a bad case of road rage.I have a similar problem - and I have figured out why - and it has helped me....
It is pretty bad, I probably need help. I get very angered by people driving in front of me. I curse/yell when I drive alone and rant to people who drive with me. I pretty much think that most people on the roads today do not deserve to drive and are clinically retarded. I have actively tried to stop driving as much and I fear that this will be bad for my stress levels / heart in the future.
I realize that some moron who is not paying attention, following the rules, yacking on the phone, applying nail polish, reading a book, all at once - all have more power than I do. That's right. They can take everything I have away from me. Allow me to explain. At any given moment, when they swerve or ram into me they will have - in the best case scenario make me late. Worst case, end my day on a permanent basis. That's not such a good thing. I get upset thinking that this ding dong in curlers can kill me.
I guess what gets me so upset is the carelessness at 45-90 miles an hour. I know how quickly FUBAR happens, and these other idiots who DON'T understand that principle. I've seen death and brains on the concrete. It's not fun. I'd rather not see it again. Especially my loved ones or my own before the lights go out.
Knowing that those other drivers are the idiots, and to be defensive helps. I assume that Murphy (who was a safety engineer) was right - if it's going to go wrong, it will. If you keep yourself busy anticipating bad moves, that you won't have time to be angry. You'll come up with some good ones. You'll be happy when it doesn't go the way you thought, and you'll laugh that you were right. Example: There's no way that lady is going to light that cigarette while on the phone at this speed! Holy spit! She did it. Ah, but she only swerved two lanes instead three... well, there's always this guy passing me on the right. Maybe he'll hit her...
Hope that helped
[Hey, when did I become an advice guy?]