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.

Traffic engineers are quietly working on a radical idea: adding a white signal to the familiar red, yellow, and green. Instead of signaling drivers directly, the extra light would tell humans when to ...

Modern traffic light technology isn't just a simple sequence of red, yellow, and green. It's a complex detection system designed to manage traffic flow based on real-time demand. The very first "smart ...