Red and green traffic lights have been around since the 1800s, when British traffic officers used to rotate gas lamps that burned red and green to control the movement of mostly horse-drawn vehicles.

If you are in your car, driving through an intersection with traffic lights, you're accustomed to looking for a few types of signals — usually green, yellow, and red lights or turn arrows. These ...

Drivers experience billions of dollars in congestion costs at intersections every year. Improving traffic signal timing could help reduce costs and delays. Sometimes you sit in your car at a traffic ...