I was referring to the city engineers timing all the lights in a city. As a driver paying attention can help, but when you have several square miles of road network, with roads unequally spaced, different speed limits and all the other weird stuff they do in a real city it is not easy. It gets worse if you go from city to a metropolitan area.
I have concluded we will never convince people of that enough to change behavior (they will answer the question correctly when asked, but drive the same) thus i'm supporting transit as much as possible.