I think that Copper meant what order each side of the intersection gets to go in. Like North and South are green, East and West are red. I may be wrong. Also, in Europe, the problem is solved because the lights turn yellow after red as well as before, in order to indicate that green is coming up. Supposedly this is partly because of the higher number of stick-shifts which Americans are generally too lazy to drive. The other more logical theory is that this was adapted from racing starts which goes back to dropping the clutch etc. Just a little tidbit from the other side of the Atlantic.
Ciao!
Ciao!