Researchers at MIT are developing an app to help drivers avoid red lights and save gas.  The app is called SignalGuru.  It predicts when a traffic light will turn red and recommends a safe speed to approach the intersection in order to cruise through it without stopping.  It never recommends a speed faster than the speed limit.

The app works by mounting a smartphone to the dashboard.  The phone's camera then sees upcoming signals and figures out the interval between lights.  Researchers say they cut fuel consumption by 20-percent during test drives in Cambridge, Massachusetts.