Traffic Light

transportation · safety · cities

Three colored lights. Traffic lights use red to mean stop, yellow to mean get ready, and green to mean go. These same colors work everywhere in the world so everyone understands the signal.

Controls traffic flow. Traffic lights manage the movement of cars at busy intersections so vehicles don't crash into each other. They help organize thousands of cars moving in different directions.

Keeps people safe. At pedestrian crossings, traffic lights tell walkers when it's safe to cross the street. The lights coordinate with car traffic so pedestrians and vehicles take turns.

Called robots too. In South Africa, Zambia, and Namibia, people call traffic lights 'robots' instead. It's just a different local name for the same helpful device.

Timed perfectly. Traffic lights change on a schedule that adjusts for busy and quiet times of day. Some modern traffic lights even sense how many cars are waiting and change faster when needed.