Types of traffic lights, the meaning of traffic lights. Why are traffic lights red, yellow and green

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The world's first traffic light appeared in London near the Houses of Parliament on December 10, 1868. It was intended for carriages that had to stop to let pedestrians pass: an arrow raised up prohibited movement, and an arrow located at an angle of 45 ° indicated that you need to drive with caution. And at night, a gas lantern served as a traffic light, which was rotated by hand: while the green light, like today, allowed passage, and the red one prohibited.

site decided to figure out why the traffic light has 3 signals: red, yellow and green. It turns out that the point here is in our perception of light.

Red

The first thing that comes to mind when you mention the color red is danger. However, the main reason why exactly red was chosen to prohibit traffic is for visibility from a greater distance. According to Rayleigh's law, discovered in 1871, the longer the wavelength, the less light is scattered. Of all the colors available to the human eye (not counting purple), it is red that has the maximum wavelength and is 620-740 nanometers.

Although the Rayleigh scatter was discovered later than the first traffic light, the choice of red for the red signal was based on experience gained on the railroad, as the inventor of the world's first automatic traffic controller, John Peak Knight, was a railway engineer.

But the first traffic light did not last long: already on January 2, 1869, the gas in the lantern exploded, seriously injuring the policeman who was driving it. Because of this incident, traffic lights were banned in Britain and reappeared on the streets of London after 60 years.

Yellow

Garrett Morgan patent.

According to the same Rayleigh law, yellow belongs to the "silver" in the competition for the best visibility - its wavelength is 570-590 nanometers. Orange can be seen even better, which is why yellow often has an orange tint in modern traffic lights.

The first three-color traffic light was patented by Garrett Morgan in 1923, who then sold the patent to General Electric for $ 40,000. Legend has it that he witnessed an accident on a street corner and decided that there was not enough time for drivers to stop before as the red light turns on, therefore, it was necessary to come up with a third, warning signal. This is how the traffic light got yellow.

By the way, until the 90s of the last century, in some countries, a yellow traffic signal was used instead of a red one. The fact is that at night in poorly lit areas, the red light was poorly visible to drivers. However, after the invention of LED traffic lights, the color red was "revived" and yellow was again used only as a warning signal.

Green

The wavelength of green is 495-570 nanometers, which is shorter than that of red and green. Therefore, it is seen worse than red and yellow, but better than other primary colors available to our perception.

It is interesting that the prototype of tricolor automobile traffic lights also became railway ones. However, the "trio" of colors was somewhat different. Red indicated a stop signal, green indicated readiness, and white allowed movement. But it was difficult for train drivers to distinguish white from lanterns or stars, which led to numerous accidents. Therefore, it was decided to abandon the white color and the railway traffic light became two-color: red prohibited traffic, and green allowed.

By the way, some traffic lights in Japan use blue instead of green - and this is due to the fact that in Japanese for a long time the same hieroglyph was used to denote both green and blue.

At first glance, traffic signals are all very simple and we all know them from childhood. Red - stop, yellow - get ready, green - go. This is a very simple rule. In this article, we'll take a deeper look at this rule in the framework.

Let's find all the pitfalls hidden in the traffic lights. The most interesting will be the signals that are in the additional section of the traffic light and what signals there may be in this section. We will consider Chapter 6 of the Rules of the Road in terms of regulating traffic through an intersection with traffic signals.

6.1. Traffic lights use light signals of green, yellow, red and white-lunar colors.

Depending on the purpose, traffic signals can be round, in the form of an arrow (arrows), a silhouette of a pedestrian or a bicycle, and X-shaped.

Traffic lights with round signals can have one or two additional sections with signals in the form of a green arrow (arrows), which are located at the level of the green round signal.

Traffic signals of a white-moon color, in the form of a silhouette of a pedestrian or a bicycle, and X-shaped signals will not be considered within the framework of this article.

6.2. Round traffic signals have the following meanings:

• Green signal allows movement;
• A green flashing signal permits movement and informs that its duration will expire and a prohibition signal will soon be turned on (digital displays can be used to inform drivers about the time in seconds remaining until the end of the green signal);
• A yellow signal prohibits movement, except as provided for in clause 6.14 of the Rules, and warns of an impending change of signals;
• A yellow flashing signal allows movement and informs about the presence of an unregulated intersection or pedestrian crossing, warns of danger;
• A red signal, including a blinking one, prohibits movement.

The combination of red and yellow signals prohibits movement and informs about the upcoming turning on of the green signal.

This paragraph of the SDA describes round traffic signals. The most common traffic light, which is most often found on the roads.

6.3. Traffic signals in the form of arrows in red, yellow and green have the same meaning as the round signals of the corresponding color, but their effect only applies to the direction (s) indicated by the arrows. In this case, the arrow, allowing a left turn, also allows a U-turn, if this is not prohibited by the corresponding road sign.

The green arrow in the additional section has the same meaning. The off signal of the additional section means the prohibition of movement in the direction regulated by this section.

The first thing you should pay attention to is that the signals are made in the form of arrows, i.e. the arrow is the signal. The signal is not circular. Traffic signals with a contour arrow do not fit this definition and clause 6.3 of the SDA is not applicable to them.

The second important point, traffic signals made in the form of arrows regulate only indicated directions. For example, if the red arrow to the right is lit, then movement is prohibited only to the right, movement straight ahead, turn left and U-turn are not regulated by this signal.

Similarly, with the signal of the green arrow, but only on condition that the arrow is in the main section of the traffic light. It is very simple to determine, for example, at night, whether this is the main section of the traffic light or the additional one - if the section is additional, then any signal must be on in the main section of the traffic light, if there are no other signals besides the arrow, then this means that the arrow is in the main section.

6.4. If a black outline arrow (arrows) is marked on the main green traffic light, it informs drivers about the presence of an additional section of the traffic light and indicates other permitted directions of movement than the signal of the additional section.

This clause describes the purpose of the traffic light outline arrow. We see that the contour arrow can be drawn only in the main section, and only on the green signal of the traffic light and, unlike the signal in the form of an arrow, the contour arrow allows movement only in the indicated directions. In other directions, traffic is prohibited.

At this point, we could finish our material, if not for one very common situation in practice. We often see a traffic light with the following signal:

Before us is a traffic light with an additional section and a round signal. It would seem that according to clause 6.3 it is forbidden to move in the direction regulated by this section.

But let's figure it out:

• According to clause 6.2, a round green signal permits movement in all directions, clause 6.3 regulates traffic signals made in the form of arrows, in this case clause 6.3 is not applicable.
• The additional section may not be visible at night, and traffic signals may not have a different meaning depending on the time of day.
• We do not know the direction regulated by the additional section, we only know that it is "different" from the signal in the main section, and in the main section we have a green signal that allows movement in all directions,
• An additional section may not contain a traffic signal at all, but be used, for example, for a timer.

Thus, with a given traffic signal, in accordance with clause 6.2, traffic is allowed in all directions, unless otherwise prohibited by signs or markings.

MIA response

Let's summarize:

• The round traffic signal extends to all directions,
• The traffic light signal made in the form of an arrow in the main section applies only to the indicated direction and does not regulate movement in other directions,
• The traffic signal made in the form of an arrow in the additional section applies only to the indicated direction and prohibits movement in other directions,
• A round traffic light signal on which a contour arrow is applied extends only to the indicated direction and prohibits movement in other directions.

And this is how the TV show “Main Road” on NTV sees the situation.

You are dear to you without obstacles!

Traffic lights are a common thing these days, and you, like all other drivers, are obliged to follow the rules: stop at a red light, prepare for a yellow light and go through a green light. There is no doubt that traffic lights should be in densely populated cities. Be that as it may, this is the only way to control traffic when there is no policeman nearby ...

Riding every day from home to office, we cannot imagine a road without at least one traffic light, but there were times when traffic lights did not exist at all. Of course, the roads were also relatively clear ... So, as already mentioned, when you get behind the wheel, you must adhere to certain rules. Traffic lights are the same all over the world and are made up of three different colors that have their specific purpose.

But how did it happen that the traffic lights are exactly red, yellow and green? Why isn't it purple, brown and gray? There are several assumptions on this topic, but first, a little history. It is no secret that the automotive industry was a pioneer in many important things that are still applied around the world, however, in turn, it also had to borrow something from other industries.

A striking example is a traffic light. The first traffic light saw the light in 1868 in London. It was used exclusively to control rail traffic at the intersection of George and Bridge Streets. The design was fairly simple, but it served its purpose very well. It was made of two vertical arrows that could move to a horizontal position when it was necessary to show the trains that they should stop. At a 45-degree angle, the system meant what yellow light does today: attention.

And now the most interesting thing: since at night the signaling device was completely invisible, the engineers decided to install primitive lights on it, which would display the "stop" and "attention" modes. What was their color choice? Red for stop and green for attention. You are probably wondering how the green light became the signal for "attention"? Well, nobody knows for sure, but that all changed a few years later when traffic lights migrated to the automotive industry.

A very important moment happened in 1912 in the United States thanks to Lester Farnsworth Wyer, who is in charge of traffic in the Salt Lake City Police Department. The first hand-operated car traffic light had only two colors: red and green. Although there were practically no cars on the roads at that time and the traffic rules were not yet spelled out, the drivers were surprised by the new invention, so the presence of a policeman was necessary to force them to obey the device.

The first three-color traffic lights appeared again on the railway, but the trio was a little different: red for "stop", green for "attention", white for "free." While the first two have a more or less obvious meaning, the white signal became a headache for the authorities. Similar lights, be they stars or streetlights, misled drivers, leading to fatal collisions.

The color red is most commonly associated with blood and thus has been chosen as a prohibition signal. Symbolizing a dangerous situation leading to serious consequences, red has always been chosen as a color to induce vehicles to stop and thereby avoid accidents. As for green, color symbolism is also the reason for its use.

As with red, green is a source of human emotion. It is associated with something relaxing (such as nature) that will not have a powerful negative effect on drivers. Also, green is easy to recognize at night. The choice of yellow was surprising. It is believed by many to symbolize the sun, which is also considered a relaxing and attention-grabbing element.

Traffic lights have evolved over the years, especially in terms of their effectiveness for color blind people. The plenipotentiaries of many countries have resolved this issue in different ways, whether it be traffic lights with double red light or sections of different shapes. One way or another, the classic design had to be changed a little. Since color blindness is one of the most common forms of visual impairment, these days red is mixed with a little orange so that color blind people can notice a stop light. For the same purpose, a shade of blue is added to green.

For example, if you painted “anger” in a yellow traffic light, then you have noticed that a dull irritation is growing inside you and you are about to break into an open expression of anger or a cry.

Green traffic light emotion Is a signal that you are okay with this emotion. The degree of its manifestation is minimal or tends to zero.

If you paint "anger" in a green traffic light, it means you are balanced and calm for today.

Color your emotions and stress in 3 traffic light colors.

Try on the 7 words below and color them in the 3 emotional traffic light colors.

What color of traffic light is dominant, is it burning now in your life?

Green? Yellow and Green? Yellow? Red and Yellow or Red?

The scale of human emotional states.

View traffic light colors distributed among these 7 emotions - what color is your emotional state ?

Are your emotions going through the roof or are they normal?

On what scale is the arrow of today's emotions frozen?

Arrow on the green scale of emotional state.

In your assessment of emotions, the color green prevails.

Most words show green traffic lights. Everything is fine. You don't need to worry.

Arrow on the orange emotional state scale.

In your assessment of emotions, red and yellow are roughly equal.

It is worth considering if 2-3 out of 7 words are red - this is a signal of danger, even if the rest of your emotions are shining with a green traffic light.

Perhaps you have recently witnessed a disaster or experienced a strong one.

Moderate stress is present in all areas of life. You are going through a divorce, dismissal, or change of residence.

Arrow on the red scale of emotional state.

Most of your emotions are in the red spectrum of traffic lights.

What sector of the emotional state scale is your arrow on? Share!

What psychological help do you need?

Depending on which color of the scale of the emotional state your arrow points to, you need one or another type of psychological help.

If your arrow points to green - You are fine and do not need psychological help. On the contrary, you yourself can safely ask for emotional support.

If your arrow is in the blue spectrum - You can still handle it yourself. Seek support from friends and family. Relax, get out into nature, sleep an extra couple of hours.

If your arrow is in the yellow or orange spectrum - You already need a psychological boost of a different kind than the support of a friend. For these colors, a good one, prepared by a professional psychologist, is suitable.

For example, an audio course of the psychologist of happiness "Healing the Soul" which contains several meditations to support and heal your Inner Child. You can do it if you do these audio visualizations with the assistance of a psychologist right now.

If your arrow is in the red spectrum - for the course on self-therapy, it is necessary to consult a psychologist who can work with emotional problems and stressful conditions.

If your arrow is in the orange or red spectrum!

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But why why why
Was the traffic light green?
And because, because, because,
That he was in love with life.

© Zinoviev N.N.

A traffic light (from Russian light and Greek φορός - "carrier") is an optical device that carries light information. We all know from childhood that traffic signals are red, yellow and green, and sometimes blue and moon-white. Red light prohibits movement, yellow light is usually a warning signal that attracts attention, and green, blue and white signals allow movement. Why are these colors used in traffic lights to control traffic around the world?

In 1868, English inventor John Peak Knight proposed using a device similar to a railway semaphore to regulate traffic in London near the British Parliament. During the day, the signals "stop" and "move with caution" were indicated by arrows that could take different positions, and in the evening, a rotating gas lamp was used for the same purposes, with the help of which, respectively, red and green signals were supplied.

At the beginning of the 20th century, the first electric traffic lights began to be installed in America, first with two signals - red and green, and then a yellow signal was added to them. In the USSR, the first traffic light was installed in 1930, but instead of the usual green signal, then blue was used. In addition, until 1959, when the USSR joined the International Convention on Road Traffic and the Protocol on Road Signs and Signals, the traffic light colors were in reverse order - the top was green and the bottom was red.

Of course, these traffic light colors were not chosen by chance. The choice was influenced by several factors, one of which is the psychology of a person's perception of various colors. Red is traditionally considered a warning of danger, and green, on the contrary, is the color of life and tranquility.

But one of the main reasons for this choice of colors is the dependence of the degree of light scattering on its wavelength. According to Rayleigh's law, the degree of light scattering is inversely proportional to the fourth power of the wavelength. This means that short-wave radiation - blue and violet - is scattered more strongly. And red, as a color with a longer wavelength, will therefore be visible from a greater distance. Obviously, the most important is the warning of danger and prevention of emergencies, therefore the stop signal is indicated in red. For the same reason (the degree of scattering), the blue signal, as having a shorter wavelength and scattering more strongly, gave way to green.

Surprisingly, in Japan, a green traffic light is called blue. The fact is that when the first street traffic lights appeared in Japan, the signals in them were red, yellow and blue. Over time, the blue lenses of traffic lights were replaced by green ones, but the custom of calling the traffic permitting signal “blue” remained. The peculiarity of the Japanese language is that, therefore, the Japanese call many green objects blue.