In the mid-to-late 19th century in Britain, with the deepening development of the Industrial Revolution, large cities such as London rose rapidly and became the world's economic and cultural center. At the same time, the number of horse-drawn carriages, as an important means of transportation at the time, also increased dramatically. Horse-drawn carriages shuttled through the streets, bringing busy traffic scenes, but also caused a series of traffic problems. Streets are often blocked by horse-drawn carriages, traffic accidents occur frequently, and the traffic order in the city becomes chaotic.

In order to solve this problem, British mechanic De Hart (some say Nayit) began to think about how to improve traffic conditions.

Once, he went to Yorkshire in central England and saw a very interesting phenomenon on the street. It turned out that there was a custom there that married women wore red clothes, while unmarried girls wore green clothes, which made them easy to tell apart.
He observed the driving patterns of horse-drawn carriages, analyzed the causes of traffic accidents, and finally designed the world's first red and green gas traffic light that was manually operated.

This signal light was originally installed in the square in front of the Parliament Building in London to direct the passage of horse-drawn carriages.

It can be seen that traffic lights were originally designed to direct horse-drawn carriage traffic.

The working principle of traffic lights is very simple but effective. When the red light is on, it means that the carriage needs to stop and wait; when the green light is on, the carriage can pass.

In this way, traffic lights successfully controlled the flow of horse-drawn carriages, reduced the occurrence of traffic accidents, and improved the traffic conditions in the city.

The birth of traffic lights not only solved the problem of horse-drawn carriage traffic, but also laid the foundation for later automobile traffic. With the popularization of cars and the increase in traffic flow, the role of traffic lights has become increasingly important.

Today's traffic lights have been automated and intelligent, and can adjust the timing of signal lights in real time according to traffic flow to improve road traffic efficiency.

The invention of traffic lights is not only a technological innovation, but also a manifestation of human wisdom. Its birth not only solved the traffic problems at the time, but also laid the foundation for the subsequent development of traffic.

Today's traffic lights have become an indispensable part of modern cities. They will continue to protect our travel safety and witness the progress and development of human society.