"tim..." wrote in message
...
right turn on red came about because it's normal not to find pedestrian
phases on US lights

peds cross the side roads at the same time as traffic runs "across", so if
you want to make a turn you can't do it then because the road is full of
crossing peds

so right turn on red is allowed instead

How does that work? You've got a stream of cars. Most of them want to go
straight on. One wants to turn right. He has a green light but he is blocked
from turning by the pedestrians. So he has to stop, blocking all the traffic
behind him until he gets a red light. That's assuming that there isn't a
separate lane for turning right, which allows straight on traffic to get
past on the left.