I sat in traffic for a few minutes today at a broken stop light—you know, the sort of broken where it flashes red in all four directions.
I noticed that jackasses running through the light when it's not their turn don't actually screw things up all that much. At most, it makes the cars in the other direction pause halfway through the intersection to let that joker through, but once things get rolling again everything resets just fine.
In contrast, drivers who don't go when they're supposed to (ostensibly due to inattentiveness) throw things way out of whack. There's a mini stand-off and drivers in the other direction start creeping forward to keep things moving, and when things do uncork it's not particularly orderly. I noticed it took two or three other directions to make their way through the light before everything was properly reset.
Ive always been amazed at how well traffic actually flows under these conditions.