One issue of eliminating the right turn on red, is when then do cars turn right?  It can be impossible to turn right on a green due to pedestrians crossing the entire time even when they have the no walk signal. There would need to be a dedicated right turn signal and time when pedestrians are completely restricted, although the few intersections I am aware of that have them, the pedestrians are notorious for failing to observe them and consider the car's green turn light their right to walk.