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.

At first glance, traffic lights are stunningly simple: green means go, red means stop, and yellow means it’s about to turn red. But like cars, phones, and just about everything else on this planet, ...

There's a new pedestrian crossing signal in town. Rather than relying on long-standing laws requiring motorists to stop for pedestrians in a crosswalk, the Pedestrian Hybrid Beacon uses yellow and red ...