I have a friend who cycled a long time ago, committed some minor infraction, and was thumped so hard by the driver he had a detached retina. What is it about the UK road system that makes people so incredibly angry that they think it is OK to swear, abuse and attack each other?
In New York City, where we lived recently there was plenty of really bad driving (tailgating, weaving, and refusing to merge properly being just a few local tactics). However it was also the safest place I have ever been as a pedestrian, because the roads were designed with cross walks at every junction (and in between) and because the rule is that as a driver you have to give way. The result is that in residential areas the cars go much much slower, and take a great deal more care. IT was a far more pleasant driving experience, and meant that I could happily let my kids walk to their friends houses and to and from school.
If you go on defensive driving courses you will find that the safest drivers (the ones that go slower and more steadily, and pay attention to their surroundings) often get to their destination as quickly or quicker than those who speed whenever they can, gun up to traffic lights, and live in permanent rage at anyone who dares to use the same roads as them.
This of course applies to cyclists and pedestrians as well as drivers, but there is one difference for cyclists, and that is maintaining momentum. The only light I have ever planned to jump is nearly at the top of a steep hill, with a merge to the left. It is little bother as a car driver to stop and start again, but as a cyclist it means losing all the hard worked for momentum, and kicking off again. As there is a bus turn left I always take it, I do feel bad about doing it, but hills are a factor for cyclists, which I always bear in mind both as a pedestrian and a driver.