Detailed Development of LED traffic lights

Traffic lights usually lights of red, yellow, and green lights composition used to direct traffic. When the green light to allow vehicles to pass, when the yellow light, has crossed the stop line of vehicles that can remain in use; when the red light vehicular traffic.
History of traffic lights

Early 19th century, in central England city of York, red, green containers represent different identities of women. Among them, the woman in the red dress, said I have to get married, and a woman with green dress is unmarried. Later, the British led street light wholesale in London occurred before the carriage rolled frequent accidents, so people inspired by the red and green dress, December 10, 1868, the first member of the family lights was born on Parliament Square, London, by the time Morality ?? Hart British mechanical design, manufacturing lamppost seven meters high, the body hanging from a red, green and white lanterns - gas traffic lights, this is the first city street lamp lights. In light of the foot, a hand-held pole police arbitrarily affect the color of the belt converter lantern. Later in the center lights mounted on the gas lamp, front it has two red and green glass alternately blocked. Unfortunately, the only available 23 days from the off gas lamp exploded, so a policeman on duty and thus ruin their lives.

Since then, the city's traffic lights were banned. Until 1914, in Cleveland, the United States was the first to restore the traffic lights, but this time is "electric lights." And later in New York and Chicago and other cities, have been re-emergence of the traffic lights.

Appear red yellow and green traffic lights

With the need for the development of various modes of transport and traffic control, the first light veritable three-color light (red, yellow, and green flag) was born in 1918. It is surrounded by three-color circular projector is mounted on a tower fifth Street in New York City, since its birth, the urban traffic greatly improved.

The inventor of the yellow lights of the Hu Ruding, him with "Science Saves the Nation" vision to the United States to study, in the great inventor Thomas Edison as the chairman of the US General Electric Company waiter. One day, he stood in the bustling crossroads waiting for the green signal, when he saw the red light and was about the past, a call to turn the car soon passing, threatened him in a cold sweat. Back to the dormitory, he repeatedly pondering, and finally thought of red, green in the middle plus a yellow light, a reminder of the danger. His suggestion was immediately sure interested parties. So red, yellow, and green lights that is a complete command signal family, throughout the world by land, sea and air transport sector a.

China's first street light

China's first road traffic lights, is in 1928 appeared in Shanghai's British concession.

Traffic lights and transport

Pull the belt from the earliest hand-to-electrical control in the 1950s, and from the use of computer-controlled to a modern electronic timing control, traffic lights constantly updated on the scientific, automation, development and improvement.

Traffic lights are African-American Garrett? Morgan in 1923 invention. Earlier, railway transport has been used to automatically convert light signals for some time. However, because the train is a fixed timetable to single run, but the train is not very easy to stop, so the signal used on the railway is only one command: traffic. Highway traffic lights are not the same, it is largely the responsibility to tell the bus driver to stop the vehicle.

Drive people who do not want to see the stop signal. University of Hawaii psychologist James pointed out, people have a tendency to brake and accelerator with self-esteem interrelated. He said: When drivers see the yellow light, my heart secretly ready to accelerate preparations. If at this time the red light, will soon produce a feeling of disappointment. He intersection called "psychological dynamic area." If his theory holds, this area in Floyd psychology theory should belong to the super-ego (supere go) rather than instinct (id) category.

The new traffic lights can take pictures of people running red lights down. Delinquent drivers will soon receive a ticket. Some lights also have the function of monitoring the vehicle speed.

The first traffic lights appeared in 1868 London, UK. Then the traffic light only red, green and white, the improved, then increase a yellow light, red light means stop, yellow light indicates ready, the green light indicates traffic.

Impact on traffic light color vision

In fact, with these three colors to make traffic signals and human visual function structure and psychological response.

Our retina contains rods and three kinds of cone photoreceptor cells. Rod-shaped cells are particularly sensitive to yellow light, respectively, to red, green, and blue three most sensitive cone cells. Because of this visual structure, people most likely to distinguish between red and green. Although the yellow and blue are easy to distinguish, but because of the eye, blue-sensitive photoreceptor cells less, so to distinguish color, or red, green better. So, what color the traffic light is also a university asked to!

Color also has implications activity (activity), and to the expression of heat or severe, then the strongest red, followed by yellow. There are cooler and quiet green implications. Therefore, people often red for danger, yellow alert, green for safety.

Moreover, since most penetrating red, other colors of light are easily scattered, not easily visible in the fog, and the least likely to be scattered red light, even though the air is relatively low visibility, can easily be seen, accident does not occur. So we use red prohibited.

Relevant laws and regulations

Regulations for the Implementation People's Republic of China on Road Traffic Safety Law

Article 38 lights and non-motor vehicle lights, said:

(A) When the green led street lighting fixture to allow vehicles to pass, but the turning of the vehicle may not hinder the release of the straight vehicles, pedestrians;

(B) when the yellow light, has crossed the stop line of vehicles that can remain in use;

(C) when the red light vehicular traffic.

In non-motorized vehicles are not set lights and crosswalk lights junction, non-motorized and pedestrian traffic shall be expressed in accordance with the vehicle lights.

When the red light, turn right vehicle to be released without prejudice to the vehicle, in the case pedestrians can pass.

Article 39 of the crosswalk lights, said:

(A) When the green light to allow pedestrian crosswalk;

(B) when the red light is prohibited pedestrians entering the crosswalk, but has entered the crosswalk, or you can continue through the centerline of the road to wait.

Article 40 of the driveway lights, said:

(A) When the green arrow lights, permitted by indicating the direction of the vehicle traffic lane;

(B) when the red light or arrow light fork prohibit vehicular traffic lane.

Article 41 indicates the direction of the arrow direction lights to the left, up, right, respectively, turn left, go straight, turn right.

Article 42 flashing warning lights flashing yellow light for sustained, suggesting the vehicle, pay attention to pedestrians when Outlook, confirm safe passage.

Article 43 roads and railway level crossing has two alternately flashing red light or a red light, it means that prohibit vehicles, pedestrians; when the red light is off, allowing the vehicle, pedestrians.