Many, many, if not most intersections have that little walk light that starts counting down. That gives a driver a pretty precise idea of when the light is going to turn. If you are approaching the intersection and the little white walking man is lit up, you can probably just maintain your speed and go through the intersection. But as you're approaching, if you see that it is counting down in red numbers, and it's at number two, and you're still a ways back, you probably better plan on stopping. No excuse from running a red light when it's already turned red!!!