How about a laser projected sheet of light that enters your car from projectors at the side of the road about 30-50 meters ahead of the intersection -- thus creating a brief by obvious flash of red on the INTERIOR of your car? The laser projector would be calibrated to switch off if any object in the 3 lanes adacent to it is moving at less than 20 MPH. An oscillating mirror would scan the laser across the plane that cars would penetrate well ahead of the intersection... and hopefully, the scanning action will make the light sufficiently diffuse such that pedestrians on the opposite side of the street (side where traffic is _departing_ intersection) would not be blinded by the laser light passing their way.

And for good measure, all the lasers of a city traffic control system could be slaved to a central computer that receives NORAD data. This would also help out in the new missile defense -- blasting incoming warheads with hundreds of converging lasers ... (OK, that last part is a little James-Bond/Science Fiction).