You nailed it sidevalve, people can't wait 10 seconds anymore, they have to barge through even when its not their 'right of way' and if anyone causes a few seconds delay in their passage, well its too much for them to bear. Even a simple look now can get you a blast from the drivers horn.
Unfortunately its behaviour not just reserved for those driving motorised vehicles. I see cyclists on shared paths going too fast, cyclists going up the curb and then using a pedestrian crossing because they can't wait 2 minutes or so stopping at a red. Cyclist going across a pelican crossing against the red light when peds are crossing etc etc.
I'm afraid its the human condition.
That being said I guess not all cyclists and car drivers get an attack of bad manners when out on the road.