I notice regional differences in green jumping behavior. In Connecticut I used to have a hard time because I would be turning left and the light would turn green and I would yield for on-coming traffic and the person going straight in the opposite direction would end up honking at me because it was expected by default that the person turning left would jump. Even though I consider it to be illegal behavior, I kind of think that it is more important to be predictable than to follow the letter of the law. I never did get to feeling comfortable driving in Connecticut because of this contradiction.