Traffic Lights

Traffic lights help keep roads safe. They use three colors to send messages to drivers. Red means stop, yellow means slow down, and green means go. Without traffic lights, busy streets would be very dangerous.

How They Started

The first traffic light was set up in London in 1868. It used gas lamps and had to be turned by hand. Later, a man named Garrett Morgan made a better traffic signal in 1923. Electric traffic lights soon spread to cities all over the world.

How They Work

Traffic lights follow a set pattern that changes every few seconds. Some lights use timers, while others use sensors in the road. These sensors can tell when cars are waiting. Smart traffic lights help cars move more smoothly through busy streets.

Fun Facts

• The first traffic lights used gas and sometimes exploded.
• Japan often uses blue-green lights instead of green.
• There are special traffic lights just for bikes and buses.

Did You Know?

In some towns, traffic lights can talk to cars to help them avoid stopping. This helps save gas and time.