I used to arrive at work all sweaty of road rage – samt thing when I came home. I realised I couldn’t change other people’s behaviour, and that I had to change my own reaction to them.
It took me about a year. Every time I got angry at some random idiot I started thinking, almost like a mantra: “Don’t worry, no point in getting angry, take it easy. It’s an idiot, but there’s nothing you can do about it and it will not help you to get angry.”
Nowadays I’m much more relaxed, and while I still find most of humanity sickening I don’t get all worked up about it.