Smart traffic lights

 Welcome to the world of smart traffic lights that can keep traffic moving, and thus limit idling vehicles. One product out there in the ethos is Green Light by Google. 14 cities are using smart traffic lights. Smart traffic lights utilize data from internet-connected vehicles and/or from navigation apps on their drivers’ phones to help adjust the timing of their traffic lights.  

WSJ | The Smart, Cheap Fix for Slow, Dumb Traffic Lights