A large part of the road rage problem is HOW the party being raged at REACTS / RESPONDS to the event. 99.999999999% of the time doing anything other than responding extremely politely and calmly and not adding to the tension by honking profusely or yelling or flipping them off or anything else that will guarantee that the situation escalates even further will ultimately cause you the initial victim to become the rager and that is guaranteed to be a problem. 

Life is too short to allow some random stranger to put you into a foul mood. You control how you respond to every situation, so choose not to engage. You will be happier, you won't be in jail for assault and battery or worse, and you will be able to have a peaceful relaxing evening by just letting it go. On the occasions where someone is driving like an idjit,the worst I will do is to flip them off *under* my steering wheel. No one can see it and it releases the tension in a safe way. It doesn't happen often but it definitely diffuses the situation for me.