Traffic light arrangement of flowers. Traffic light: colors in order, description and meaning

Today, everyone understands what a traffic light is. Colors: red, yellow and green are familiar even to a child.

However, there was a time when these optical devices did not exist, and it was not very easy to cross the street. Especially in large cities, passers-by had to let endless horse-drawn carts pass for a long time.

There was confusion and endless disputes on the cross streets.

A small digression into history

Traffic lights were originally invented by the British. It was staged in London at the end of 68 of the 19th century. It was run by a man. The mechanism had two arrows. When they were in a horizontal position, movement was prohibited, and when lowered, passage was allowed. Turned on at night gas burner, which gave a red and green signal. It turned out to be unsafe. The gas exploded, wounded a policeman, the traffic light was removed.

Only at the beginning of the twentieth century in America was an automatic traffic light patented. Colors were not used in it, their inscriptions replaced them.

The red color is very clearly visible in any weather: when the sun is shining brightly, it is raining, or there is fog. From a physical point of view, red has the maximum wavelength. Perhaps that is why it was chosen as forbidden. All over the world, the meaning of red is the same.

The other traffic signal is green. This is the color of calmness, peace. It has a relaxing effect on the human brain. Green allows movement. It can be seen far enough, any driver sees this color long before the traffic light passes and calmly, without braking, overcomes the intersection.

However, as they say, there is an unwritten rule according to which it is still worth slowing down when driving through a dangerous intersection, even when the traffic light is green. This action often helps to avoid serious accidents.

Yellow - pay attention

The yellow color of the traffic light is intermediate. It has a warning function and encourages road users to pay attention. It is said that yellow symbolizes the mind, intuition and ingenuity. It usually lights up after red, urging drivers to prepare for movement. As practice shows, many drivers perceive the yellow signal of a traffic light as permissive and start moving. This is wrong, although it is not punishable by penalties. When the yellow color lights up, you need to squeeze the clutch, get ready, but to start moving it is better to wait for the green one, especially since you only have to wait a couple of seconds.

In reverse order: green, yellow, red - the traffic light is not working. In modern devices, after the green, the red color immediately lights up, while in the last minutes the green starts flashing.

You can also sometimes see a continuously flashing yellow traffic light. This indicates that the traffic light is disabled or broken. Most often, traffic lights flash yellow at night.

Pedestrian traffic light

There is also a traffic light to regulate pedestrian traffic. What colors does it use? Red and green - definitely, but yellow is missing as unnecessary. A person does not need special preparation for crossing the road.

They are usually depicted as walking men. For the convenience of pedestrians recent times time counter is used. A special stopwatch counts how many seconds are left before the opposite signal is turned on.

As in conventional traffic lights, red indicates traffic is prohibited, while green indicates that the passage is open.

When passing through an intersection, drivers should be aware that pedestrians are taking advantage. So, for example, at a crossroads, a car turns right at a green traffic light, while pedestrians crossing a perpendicular road also light up green color. In this case, the motorist must give way to all pedestrians and only then continue driving.

What is a "green wave"

In large metropolitan areas, traffic on highways is accompanied by a large number of traffic lights that regulate traffic. The traffic light, the colors of which are known to everyone, switches them at a certain frequency. This frequency is automatically adjusted and ensures the safety of vehicles.

"Green wave" is tied to the speed of the car. It is assumed that, moving at a certain average speed, the driver, hitting the green traffic light, will also get green along the entire length of the highway. The three colors of the traffic lights switch at regular intervals, and there is consistency between a number of traffic lights. At all intersections of the route, coordinated according to this principle, there is the same cyclicity.

The "Green Wave" was developed for the convenience of crossing intersections; technically, this is not particularly difficult to implement. As a rule, signs are additionally installed on such highways with the recommended speed, which will ensure non-stop passage of intersections.

An assistant to the driver and pedestrian is a three-eyed traffic light. The colors switch in order and adjust the ride, ensuring the safety of all road users. Observing in good faith, you can avoid serious accidents and unpleasant situations on the roads.

At first glance, traffic lights 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 within the .

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

Depending on the purpose, traffic light 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 may 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 white-moon color, in the form of a silhouette of a pedestrian or a bicycle and X-shaped, we will not consider in this article.

6.2. Round traffic lights have the following meanings:

• Green signal allows movement;
• A green flashing signal allows movement and informs that its time expires 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);
• The yellow signal prohibits movement, except for the cases provided for in paragraph 6.14 of the Rules, and warns of the upcoming 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 flashing, prohibits movement.

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

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

6.3. Traffic light signals made in the form of arrows of red, yellow and green colors have the same meaning as round signals of the corresponding color, but their effect extends only to the direction (directions) indicated by the arrows. At the same time, the arrow that allows a left turn also allows a U-turn, unless this is prohibited by the corresponding road sign.

The green arrow in the additional section has the same meaning. The switched 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 round. Traffic lights 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 light signals made in the form of arrows regulate only indicated directions. For example, if the red arrow to the right is on, then movement is prohibited only to the right, movement straight ahead, turning left and turning around are not regulated by this signal.

Similarly with the green arrow signal, 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 some 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 sections.

6.4. If a black contour arrow (arrows) is applied to the main green signal of the traffic light, then 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 paragraph describes the purpose of the outline arrow of a traffic light signal. We see that the contour arrow can only be applied in the main section, and only on the green traffic light, and unlike the signal in the form of an arrow, the contour arrow allows movement only in the indicated directions. Movement in other directions is prohibited.

On this we could finish our material, if not for one very common situation in practice. We often come across a traffic light with such a signal:

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

But let's take a look:

• According to clause 6.2, a round green signal allows movement in all directions, clause 6.3 regulates traffic lights 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 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 light at all, but can be used, for example, for a timer.

Thus, at this traffic light signal, according to clause 6.2, movement is allowed in all directions, unless otherwise prohibited by signs or markings.

Let's summarize briefly:

• The round traffic light 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 traffic in other directions,
• The traffic light 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 applies only to the indicated direction and prohibits movement in other directions.

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

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The first thing that comes to mind at the mention of red is danger. However, the main reason why red was chosen to prohibit movement is 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 magenta), it is red that has the maximum wavelength and is 620-740 nanometers.

Although Rayleigh scattering was discovered later than the first traffic light, the choice of red for the prohibition signal was based on experience gained in railway, after all, 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 lamp exploded, seriously injuring the policeman who was driving it. Because of this incident, traffic lights in Britain were banned and reappeared on the streets of London after 60 years.

Yellow

Patent for an invention by Garrett Morgan.

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 in modern traffic lights often has an orange tint.

The first three-color traffic light was patented by Garrett Morgan in 1923, who then sold the patent to General Electric for $40,000. According to legend, he witnessed an accident that happened on a street corner and decided that drivers did not have enough time to stop before as soon as the red light turns on, therefore, it was necessary to come up with a third, warning signal. So the traffic light turned yellow.

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

Green

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

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

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

The order of alternation of traffic lights corresponds to the international Convention on Road Signs and Signals. Traffic lights alternate in the following sequence: red - red with yellow - green - yellow - red. Alternation of signals red - green - yellow - red or red - yellow - green - yellow is allowed.

A red solid signal prohibits movement across the entire width of the carriageway. Varieties of the red signal:

A contour black arrow on a red background of a round shape prohibits movement in the direction of the arrow;

An oblique red cross prohibits movement along the lane over which it is installed;

The red silhouette of a man forbids pedestrian traffic;

Red flashing prohibits entry to a railway crossing, bridge, pier, etc.

A yellow solid signal obliges all drivers to stop before the stop line, with the exception of those who could not stop before the intersection.

Yellow connected to red warns that the green signal is on.

A yellow flashing signal warns of the presence of an intersection and does not prohibit movement.

A green steady signal in the absence of any additional sections of the traffic light allows movement along the entire width of the carriageway in all directions.

Varieties of green signal:

A black arrow on a green background of a square, round shape, as well as a green arrow on a black background of a round shape - permission to move in the direction of the arrow;

A green arrow on a black background of a square shape, pointing down, allows movement in the lane over which it is installed;

A signal in the form of a green silhouette of a person allows pedestrian traffic;

The green arrow of the additional section of the traffic light allows movement in the direction of the arrow, regardless of the signal of the main traffic light;

A flashing green signal warns of the end of the enable signal.

Permission for the movement of public transport depends on the combination of the included signals of the upper and lower rows of a special traffic light. Turning on the lower signals movement is prohibited in all directions.

Studies have shown that there is a so-called critical section before the intersection and, being within this section, the driver cannot stop in time in front of the stop line when changing the permissive signal to prohibitive.

The critical section is defined as the distance from the stop lines to the point where 10% of drivers cannot stop. The length of the critical section depends on the speed of movement. So, at a speed of 50 km/h, the length of this section is 43 m and the travel time for this section is 3.1 s; at a speed of 60 km - the length of the section is 58 m and the travel time is 3.5 s; at a speed of 80 km - the length of the section is 91 m and the travel time is 4.1 s.

Hence, the travel time of the critical section at different speeds varies within 3-4 s. This prompted us to use a flashing green signal as a warning and take the flashing time equal to the time of passage of the critical section. In order not to reduce the throughput of the intersection. with a permission signal, a green flashing signal is introduced in part at the expense of the duration of the yellow, which will allow you to safely pass the intersection.

Types of traffic lights. Traffic lights are classified according to their functional purpose - transport and pedestrian; by design - one, two-section, three-section and three-section with additional sections; according to the role performed in the process of motion control - the main ones, backups and repeaters.

The main two groups of traffic lights: transport and pedestrian, which in turn are divided into types. There are 8 types of traffic lights and 2 types of pedestrian ones. The first traffic light number means the group, the second number - the traffic light type.

traffic lights Type 1 have three round signals with a diameter of 200 or 300 mm, arranged vertically or horizontally.

The first type is used with additional sections, in which arrows indicate the direction of movement (arrows on a black background). Traffic lights of this type are used to regulate all directions of traffic at intersections. Their use is allowed at railway crossings, intersections with tram and trolleybus lines, in narrowings of the carriageway, etc.

Traffic lights 2 types. On the lenses of the traffic light, the contours of the arrows are applied. indicating permitted or prohibited movement. In this case, the green signal (arrow) is applied on a black background. Type 2 traffic lights are used to regulate traffic in certain directions (indications on the arrow lens).

Traffic lights type 3. They are used as repeaters and in conjunction with type 1 traffic lights.

They are installed under the main traffic light at a height of 1.5-2 m from the roadway. The diameter of the signals is 100 mm. If the main one has an additional section, then the repeater will be equipped with an additional section. Traffic lights of this type can be installed to control cycling.

Traffic lights type 4. They are used to control entrances to separate traffic lanes, with reverse traffic.

They are installed above each lane at its beginning. They have horizontal arrangement signals; on the left - in the form of an oblique red cross, on the right - in the form of a green arrow pointing downwards. Both signals are performed on a black rectangular background. Overall dimensions 450 x 500 mm.

These traffic lights can be used together with type 1 traffic lights if the reverse traffic is not organized across the entire width of the carriageway. In this case, the type 1 traffic light does not apply to lanes with reverse traffic. This lane may be delimited by a double broken line 1.9 when the type 4 traffic light is turned off.

Traffic light type 5. Has 4 signals of pale moon color of a round form with a diameter of 100 mm. This traffic light is used in cases of conflict-free regulation of the movement of trams, shuttle buses, trolleybuses moving along a specially allocated lane. In the scheme of organization of traffic at the intersection, a conflict-free passage is provided, i.e., these types together with the general flow, therefore, there is no need to use this type at the intersection.

Traffic light type 6. It has two (or one) round red signals with a diameter of 200 or 300 mm, located horizontally and operating in the alternate flashing mode. When the signals are off, movement is allowed. They are installed in front of railway crossings, drawbridges, berths, ferry crossings, in places where special vehicles enter the road.

Traffic light type 7. It has one yellow signal, constantly working in flashing mode. It is used at unregulated intersections of increased danger.

Type 8 traffic lights. They have two vertical signals of red and green colors of round shape W 200 or W 300 mm. They are used for temporary narrowing of the carriageway, when alternate traffic is organized along one lane. They are also used to control low-intensity traffic in the internal territories of garages, enterprises and organizations where a speed limit has been introduced.

Pedestrians have two vertically arranged signals of a round or square shape with a circle diameter or a square side of 200 mm or 300 mm. All pedestrian crossings at the intersection controlled by traffic lights are equipped.

Traffic lights with big size installed on the main streets, squares, on roads with the speed of T.S. 60 km/h

Traffic light design. The traffic light consists of separate sections (Fig. 1) and each section is designed for a specific signal. Depending on the type of traffic light, the sections have different shapes, symbols, light sources, etc. Common to all sections is the presence of an optical device placed in a separate housing.

Figure 15 - Traffic light device

The sections are interconnected by threaded hollow bushings 1, through which the supply wires are passed. The section consists of a body 8, a sun visor 4 and a cover 6. They are made of sheet steel or plastic. An optical device is mounted in the cover, which consists of a reflector 7, a colored diffuser lens 3 and a movable glass 10 with an electric lamp. When the glass is moved, the filament of the lamp is set at the focus of the reflector. To connect the current supply at the bottom of the section there is a block 9.

Light source.

As a light source, incandescent lamps are used, both for general and special purposes. So, gas-light tubes or emitting diodes are used as a light source. The main disadvantage of an incandescent lamp - for general use - is the large length of the filament, which is difficult to focus, low vibration resistance of the lamps, and also have a short service life (500-800 hours):

It has been proven that filament burnout occurs mainly due to inhomogeneity in wire diameter, helix pitch, electrical resistance and evaporation rate.

In some traffic light designs, halogen lamps are used. At small sizes, they have an increased specific light output and a compact filament, and these lamps focus well. However, these lamps were not widely used due to their high cost.

Two simultaneously working lamps can be used in one section, but this requires the installation of a special reflector and a bifocal lens. Such a solution is associated with a complication of the design and an increase in cost.

Abroad, a curved gas-light tube has found application as a light source. The tubes contain a filler of red, yellow or green colors, which eliminates the need for a colored lens. For the glow of the tubes, a voltage of over 2000 V is required, so a transformer is required. They have a long service life, but in terms of signal strength they are 5-6 times inferior to modern traffic lights with incandescent lamps.

Traffic light lenses.

AT last years In our country and abroad, plastic lenses are widely used. They have advantages over glass ones in ease of manufacture, higher strength under impact and vibration loads, as well as less weight (about 3 times). These lenses are usually made from polycarbonate.

Diffuser lenses are designed to redistribute the light flux into ■ space. To do this, they inside a patterned, rhombic, prismatic or drop-shaped pattern is formed. An important characteristic of the lens is the angle of light scattering - the largest angle within which the light intensity is halved compared to its axial value. For modern lenses, this angle is in the range of 5-15°, which ensures normal signal visibility on multi-lane roads (100 m).

Reflector.

The reflector is characterized by two main internal surfaces: paraboloid, which provides the concentration of the light flux, and conical (or cylindrical), designed to increase the depth of the reflector and thereby reduce the burnout of the lens dye.

With a short focal length, there is a danger of a false traffic signal (phantom effect), when the beam from an extraneous light source, hitting the reflector, returns to the observer again.

In the designs of modern reflectors, the focal plane AA is brought as close as possible to the plane of the light hole, behind which the non-working conical surface begins.

As a rule, the condition is met:

(13)

where: is the diameter of the light aperture of the reflector, mm.

Reflectors are made of steel, aluminum alloys or plastics with subsequent processing of the inner surface. Plastic reflectors with a working surface obtained by vacuum deposition are widely used.

Anti-phantom devices.

An anti-phantom device in a traffic light is a sun visor, but at a low position of the sun (for example, east-west, west-east), all traffic lights may glow.

There are several methods to eliminate the phantom effect, but they require a change in the design of the reflector or traffic light lens.

The reflector with the so-called anti-phantom cross consists of mutually perpendicular segmented plates with slots for the location of a halogen lamp (Fig. 1).

A beam of light falling from an external light source onto the reflector is deflected and absorbed by the surface of the plates. Another solution is carried out by installing a special anti-phantom lens in front of the light filter 1, consisting of two parts 2, 3, each of which has a sawtooth profile (Fig. 2). A ray of the sun, falling on an inclined surface, is thrown onto a horizontal blackened step and absorbed by it.

Rice. 16 - Anti-Phantom Cross

Fig. 17 - Lens that absorbs the sun's rays

Why are the colors of the traffic lights the way they are? and got the best answer

Answer from Natalya Buldina (Mortisss)[guru]




Source: => Vita pulchra et necessaria. (lat.)

Answer from Iy[guru]
Some countries use orange instead of yellow. Signals can be arranged both vertically (with the red signal always on top and the green signal on the bottom) and horizontally (with the red signal always on the left and green on the right) . In the absence of other, special traffic lights, they regulate the movement of all types of vehicles and pedestrians. Sometimes traffic lights are supplemented with a special countdown display, which shows how long the signal will remain on. Most often, the countdown board is made for a green traffic light, but in some cases, the board also displays the remaining time of the red signal.
Almost everywhere, a red traffic light signal prohibits movement, a yellow one prohibits leaving the area protected by a traffic light, but allows the completion of its passage, and a green one allows movement. It is common, but not universal, to use a combination of red and yellow signals to indicate that the green signal is about to turn on. Sometimes a green signal turns on immediately after a red one without an intermediate yellow, but not vice versa. The details of the use of signals differ depending on the traffic regulations adopted in a particular country.
There are two sections of traffic lights - red and green. Such traffic lights are usually installed at points where cars are allowed to pass on an individual basis, for example, at border crossings, at the entrance or exit from a parking lot, a protected area, etc.
Flashing signals may also be given, the meaning of which depends on local legislation. In Russia and in many European countries, a flashing green signal indicates an upcoming switch to yellow. Cars approaching a traffic light with a flashing green signal can take timely braking measures to avoid entering the intersection guarded by the traffic light or crossing the prohibitory signal. A flashing yellow signal requires you to slow down to pass an intersection or pedestrian crossing as unregulated (for example, at night, when regulation is not required due to low traffic) . Sometimes special traffic lights are used for these purposes, consisting of one flashing or alternately flashing two yellow sections.

Answer from Anastasia churilova[newbie]
Three colors are used in the light signaling of road transport - red, yellow and green.
For a person from time immemorial it has developed that red is a signal of danger, alarm. It was fire that was always such a sign for him. Red has become a universally recognized hazard warning signal. And vice versa, the green signal has always been personified with safety, calmness, so it was natural to use it as a permissive traffic light signal.
Red rays have the longest wavelength and propagate with the least loss. Therefore, the red color is visible the farthest. The red signal is more visible and it is he who is accepted as a danger signal. This is especially important, for example, in low visibility conditions. For example, fog absorbs blue and green rays, so green in fog can be perceived as yellow, and yellow as red. If a driver in fog mistook yellow for red and green for yellow, then such errors would not pose a danger to traffic.
In the beginning, traffic lights had a green signal at the top, but then it was agreed that the red signal was more important for drivers and pedestrians and therefore it should be more visible. It is no coincidence that recently they even began to make lenses for this signal larger than the others.