How do I control my road rage towards an incompetent driver?

There is a driver that I often see on the road since we live less than 1 mile from each other. Today I saw him and he was in front of me so I started doing what I normally do when I see him, I started flashing my headlights at him to let him know that I hate his driving and to consider driving safely for a change. Usually he decides that he no longer has to obey the speed limit and in some cases drives two or three times the posted speed limit. This time he slowed down and got mad at me when I started to ride his tail since he was going 1/3 the posted speed limit. He decided to intentionally slam on his brakes to cause an accident and I was able to swerve to avoid rear-ending him and the traffic behind me was able to swerve to avoid hitting me. I sounded my horn and he made an obscene hand gesture towards me. I continued to ride his tail, flash my headlights and honk. He pulled off the road into a parking lot and I followed him and blocked him in a parking stall because I wanted to have him arrested for reckless driving. I called the cops as I had him blocked but the car in the stall directly in front of this driver pulled out and the driver casually drove off while I waited for the police to arrive. They never arrived so if it happens again I will probably go ballistic and beat the tar out of this retard to teach him a lesson about safe driving. How can I control my anger especially when it is obvious the police have no intentions of revoking this person's drivers license? I have tried for year to have him removed from our roads but either the police don't do anything or he is able to p the review examination which I found out is open book so I wonder why they even have a review exam for incompetent drivers in Utah. Anybody have ideas?