In NYC, right on red is illegal and I’d venture a guess that >98% of drivers obey this. Obviously each city will need to handle it differently, but they can’t make it illegal and then call it a day. Enforcement and change infrastructure to match the new rules of the road are necessary. In the case of lowering speed limits, traffic calming measures should be put in place with the reduction in speed limit, so that going 45mph in a 25mph zone is difficult.