Saving Fuel using GPS-Controlled In-Car Stoplights

I have had an green idea that I think is maybe worth sharing with the world. With all the electricity our country wastes with stop lights at nearly every intersection, I had an idea of having GPS-controlled miniature stop lights that are on our automobiles dashboards. This would reduce the need for stoplights and the electricity they waste. Every car on the highway would have a miniature stop light on the dashboard. This miniature stop light would also have sound, voice or sound alerts such as "you're approaching an intersection, start slowing down now". Or, "The approaching stop light is now yellow". The in-car stop light would be controlled by GPS and mimic what our existing stop lights are now doing. Our highways would of course need to be mapped so the GPS maps would know where intersections exist. There's multiple benefits to this idea and a few kinks that would need to be worked out. Lights and sound would hopefully make more people alert and reduce accidents. Stop lights and the electricity needed to power them would no longer be necessary. Our automobiles electrical system would power the GPS stop light using DC current. The sensors that now sense our automobiles in an intersection would still be used, but maybe one day GPS units would also transmit our location to the traffic control system and software would control our in-car stoplights to help avoid any wasted fuel (how many times have you sat at a stop light and nobody was around!) with a more efficient means to control the flow of traffic using stop lights.