The second part is true, but illegal.
The first part, no. The grooves cut into the ground have wires in them that detect any metal above them. That would be a vehicle. This tells the light's computer that there are cars waiting in that lane and it changes the light when it is programmed to. If you are at a light and no cars are in the intersection (and it is not a major cross road that would likely have a longer time) then that light doesnt have wires in the road.
http://auto.howstuffworks.com/question234.htm