Why are the traffic lights in some places not designed in seconds?

The traffic lights in many small cities are in the form of counting seconds, and there is another traffic light that is not in the form of counting seconds. It changes the traffic lights according to the flow of people. There are two kinds of traffic lights. One is manual change, that is, someone looks at the camera at any time and then manually adjusts the time of the traffic lights. The other is more high-tech, which can sense the flow of people underground and automatically adjust the traffic lights. In some big cities in China, such as Beijing and Shanghai, such traffic lights are being used.

Countdown traffic lights and high-tech traffic lights have their own advantages and disadvantages.

Besides, automatic traffic lights really save people time. There will be no green light without a car, and many people wait for the red light on the empty road. It really conforms to the fast-paced life in first-tier cities, especially in Shanghai, where people's life is very fast. Who wants to waste time at this traffic light, even if it is less than half a minute? What are the disadvantages of this traffic light? First of all, there may be some problems with this automatic induction. I wanted to save time but wasted a lot of time. Second, I don't know when the traffic lights will change, so I don't have any psychological preparation time.

What about the countdown traffic lights? This is a very traditional traffic light. Its advantage is that you can see the red light in the distance in a few seconds, so don't worry. For example, I still have about 200 meters to see the green light and a few seconds. I'm definitely not in a hurry to catch the green light, because I know I can't catch it. There is also that people can slow down and stop in the fast-paced life to make themselves less impetuous. As for its shortcomings, it is actually the advantages of automatic traffic lights, so I won't introduce them.

Therefore, the two kinds of traffic lights have their own characteristics. Even if it exists, there is a reason for its existence. It is not necessary that all traffic lights are in the form of seconds.