In 1868, the United Kingdom mechanical engineers nayite used it on the road, and near the Parliament building in London, George Street and Hiric Street fork in the road on the cast iron columns will appear red and green rotating square glass Lantern composition, gas-fueled traffic lights. The traffic lights made from manually operated to transform a color, red for "stop" and green for "attention", is mainly for the convenience of Capitol lawmakers to work safety. In the only incident, killing one policeman on duty in the vicinity were killed on the spot, the traffic lights that no one dares to use.
Until the late 19th century, Thomas Edison invented the light bulb, for electricity-powered lights provide the birth of prerequisites. In 1914, the United States Cleveland lead back to traffic lights, but it was "electric light". Later, cities such as New York and Chicago have been renewed by the traffic lights. This lights red, green, yellow color a circle composed of light projector, mounted on v Street in New York City on one of the towers. Red light means stop, a green light means go. It later emerged with control of traffic lights and infrared lights.
In 1918, the traffic police in Detroit weilian·BOCI invented the world's first manned electric lighting "red, green and yellow" tri-color traffic signal. The traffic lights installed in the signal Tower from the center of the intersection, signals the top sides are equipped with red, green, yellow-colored circular light projector. Yellow light means go, signals a red light means stop, a green light signals that can turn around.
With the development of cars, people realized that the car is a high speed transport, if direct conversion green light red light encountered in vehicle by automotive brakes and easily hurt passengers. The tri-color signal Tower appeared in the streets, immediately welcomed. Two years later, Japan, seven years after the United Kingdom. United Kingdom provides for the tri-color light: Green means go, red light indicates stop, yellow for a warning. Traffic lights have also become an important part of the traffic composition, teacher education since childhood we want to stop at a red light, green light, yellow light to go slow, follow the rules for orderly traffic, urban transportation, at no time can leave the traffic lights. Even late at night, when traffic lights still work as usual.