Why is a "green line" traffic lights?

Today, when we approached the intersection of driving, do not need too much parking guidance has known the continued driving. We just need to see red, yellow, and green three color, and in accordance with the color. The connotation of red, yellow, green, however, is not known from the start, the three color can become a signal of the traffic light colors, or a slightly odd strange stories.

In fact, two years ago, it was traffic lights one hundred anniversary. According to the journal of historical records, the world's first electronic traffic lights, installed in the United States in 1914 in Cleveland, Ohio 105 Euclidean road east street intersection. However, this is not the first light traffic lights in the history of mankind, before this, people have the idea of installing a barricade. In 1914 just traffic lights in a report in the history of mankind.

In 1868, for the pedestrian safety, the world's first light traffic lights so born, people to install it in the parliament square in London. In earlier than 1868, nearly half a century ago, the world's first light came not power traffic lights. In the 19th century, with the increase of power transportation, people urgently need a can make the transportation more unobstructed. The international financial times (InternationalBusinessTimes) wrote:

People install the semaphore -- including a tall pole, movable arm are there on the plate. When the arm board moved to the side of the pole, a sign for parking. In the evening, the gas will be at the top of the pole lights up. A green light signal, a red light means stop.

Police human these lights, and according to the observation of the traffic change signal, they blew the whistle in front of the signal change, so as to warn vehicles and pedestrians. According to the ROYG. BIV "this book records, until a kerosene lamp explosions, this method is very effective.

In 1869, shortly after semaphore installation, because a leaking gas, kerosene and exploded. Police were manipulating light injury in an explosion. Since then, officials in London soon ended the arm board traffic signal of the project.

And in the same way as in London, the United States in the early light red lights and artificial control. According to the international financial times records, in 1920, is the first electronic traffic lights appear after four years, is a named William patzer Detroit (WilliamPotts) police will now known red yellow green traffic light scheme.

Paz is on the basis of railway signal lamp red yellow green colors, and we can only assume that the early light color is also in the same way. But according to the record of the railway signal (RailroadSignaling), railway signal lamp alternative color is white, green and red. Instructions and now different lights at the time, at that time, a green light signal warning, white light signal can be safe passage, red light then, as now, a sign for parking.

In theory, with a white light is very appropriate to sign for "all clear" - even more than was appropriate in green. However, in practical use, the white light can bring a lot of losses, life sorrow.

Railway officials began as early as 1899 the abolition of the white light signal can be safe passage. That year, the railway locomotive engineering (RailroadandLocomotiveEngineering) of one of the volume, the vehicle crash and traffic chaos because of the color of the light is too little. Red lamp is very easy to bad, it's a bad, will be left alone white lights on, signal can be safe passage, while the light is supposed to be a sign for the train: the danger ahead, need to stop. In this case, it easily cause an accident.

Author points out that railway locomotive engineering commander also often confused because of the white light. Should be replaced by white light, is replaced by other lamp, and vice versa. The reason is obvious. Colored lights in the dark and black the set off of the building is very obvious, and the white lamp, can anything and fuses in together, both the moon and lanterns, white light can be integrated.

Because of this, authorities decided to abolish the white light in the application of the railway industry. After doing so, gradually got the green light "line", "red" stop ". Railway has also increased a transitional color - yellow, as a warning. Since then, the commander can understand, yellow means warnings or parking.

These color has since passed into the history the way of traffic lights light up in the 1920 s, red, yellow, green, and after the years the various variations of the traffic lights. Today, after nearly 100 years later, see red yellow green light, we even don't want to think, can be reflected in their respective implications.

So, next time, you just need a minute before the traffic lights in town, don't need to bother to pay attention to other vehicles in the distance, as long as you can be sure the drivers are staring at the lights on.