Yesterday I was driving past midnight through the city. I&#x27;d frequently come to an intersection where 2 arterials crossed at 90 degrees. 3 of the roads had red lights and 2 or more cars backed up. The 4th had a green and no traffic coming at all. And ..... we&#x27;d sit there a while, and eventually the light would go yellow, again, for nobody, turn red, pause a second for the non-existent red light runners, then finally turn green for us.<p>The intersections had cameras mounted pointing all 4 ways, and sensor wires in the roads.<p>You&#x27;d think that if we could build self-driving cars, we could devise a traffic light that would not be monumentally inefficient and incompetent. How hard can it be? And think of all the gas, CO2 and time saved.<p>There&#x27;s a heluva lot of low hanging fruit in traffic lights.