Traffic lights are an important part of our city, but how many people know the source of development? First originated in the 19th century when the traffic lights of the United Kingdom, at the time married does Red mean, green is the second representative of the single meaning. When the United Kingdom often carriage man's accident, some mechanic was designed only two colors of traffic lights the gas. But involves manually bring switch colors. Traffic signals and other more power after replacing the original gas lights.
Traffic lights were first appeared in 1923 the British concession in Shanghai, and manually by traffic police to control traffic lights. And the yellow light is the intelligence of Americans. And traffic light after years of development, has been continued to the present.
With the development of society, more and more traffic in the crowded city traffic in some of the traditional ways to solve problems. Road congestion is also growing because of road congestion cause more traffic accidents occurred, causing economic losses and more. Therefore, the manufacturer of traffic signals as early as possible to come up with a solution is imperative.