>>I don't know where you drive, Mark, but we have many intersections with big banks of various numbers of lights for turns, etc., around here :)
>
>But even then, the red light is always on top of the yellow light which is on top of the green light, even for arrows, right?

No, I believe usually there's one arrow for each direction, and it changes color...say, I guess we need a real color-blind person who knows all about this to weigh in and let us know the traffic safety issues :)