that the choice of colors for traffic lights fell on the red, yellow and green, and white and blue, it is due to two main reasons. One of these phenomena is in physics, another person in psychophysiology. The colors have different effects on their expressiveness. Take, for example, conventional steel door. Bright color tone and paint the door makes it feels a person less severe. Dark colors including black design make steel doors feels more massive. The expressiveness of color is particularly evident in advertising. Those pillars, with bright sunny colors colors attract a man and pay much more attention to the existing text and image than pillars, decorated in soft shades of blue or green. At the traffic lights, should be encouraged to pay attention to changes in the situation when you change the color of a traffic light, and then apply color having a stimulating effect of a warning - yellow. Red is often in the nature of many living things is a sign of danger is very close located. Therefore, the ability to move the pedestrian is a dangerous situation for two people on the road and the red signal excites the nerve centers of the driver and a pedestrian, indicating the presence of close opasnosti.
It should also be said that these three colors are best perceived by the human eye in its physical parameters and the wavelength inherent. The sensation of red and green color signals as banning and prohibiting the movement must be clearly identified without the possibility of error. What is observed. Even color-blind do not disassemble the colors of gray tone can accurately respond to the traffic light red or green. Although this definition of human physical defect greatly weakened. That's why there is a ban on driving with this disease. It should be clearly understood that a person's vision to light of different wavelength of light reacts with greater or lesser sensitivity. To select the resolution of green light due to the maximum approximation to the level of that color is most clearly perceived by part of the spectrum. It is seen in contrast to other traffic light with the highest possible distance. Because, as the higher sensitivity of the eye at 555 nm. And the perception of the green, which has a range of values of 500-550 nm range, at different times of the day does not fall below 0.5 of the maximum sensitivity, both in daytime and twilight observations. See also: Why Einstein showed language? Why do we hear in a seashell "sound of the sea"? Why is not recommended while reading a book and listening to music?