Abstract: A traffic routing system reduces emissions from commuter and other traffic, eases congestion on roadways, and decreases transit time by use of communications among vehicles and traffic controls, such as traffic lights. In one aspect, a traffic light receives a signal that a vehicle is approaching and in response turns green to allow the vehicle to pass without impairment. In another aspect, a vehicle receives a signal to adjust a current rate of speed to arrive when a traffic signal allows vehicles to pass. In still another aspect, a combination of congestion, emergency traffic, roadwork and similar factors influence proposed routes sent to vehicles.