Currently, LED traffic lights around the world use red, yellow, and green. This selection is based on optical properties and human psychology. Practice has proven that red, yellow, and green, the colors most easily noticed and with the longest reach, represent specific meanings and are most effective as traffic light signals. Today, traffic light manufacturer Qixiang will provide a brief introduction to these colors.
(1)Red light: Within the same distance, red light is the most visible. It also psychologically associates “fire” and “blood,” thereby producing a sense of danger. Among all visible light, red light has the longest wavelength and is highly suggestive and easy to identify. Red light has low scattering in the medium and strong transmission ability. Especially in foggy days and when the atmospheric transmittance is low, red light is most easily detected. Therefore, red light is used as a signal to stop passing.
(2) Yellow light: The wavelength of yellow light is second only to red and orange, and it has a greater ability to transmit light. Yellow can also make people feel dangerous, but not as strongly as red. Its general meaning is “danger” and “caution”. It is often used to indicate a “warning” signal. In traffic lights, yellow light is used as a transition signal, and its main function is to warn drivers that “the red light is about to flash” and “no further passage”. Etc.
(3) Green light: Green light is used as a signal for “allowing passage” mainly because green light has the best contrast with red light and is easy to identify. At the same time, the wavelength of green light is second only to red, orange and yellow, and the display distance is longer. In addition, green makes people think of the lush green of nature, thus creating a sense of comfort, tranquility and safety. People often feel that the green color of traffic lights is bluish. This is because according to medical research, artificially designing a green light can improve the color discrimination of people with color deficiency.
Why use color instead of other signs:
The reaction time of color selection is fast, the color has low requirements for the driver’s vision, and it is the color used by the earliest traffic signals.
Why use red, yellow and green: The three colors can represent more traffic conditions, red and green, yellow and blue are antagonistic colors that are not easy to confuse, and red and yellow have a cultural meaning of warning.
Why are traffic lights placed from left to right and from top to bottom: It is more likely to be consistent with the order direction in culture, consistent with the direction of our language habits, and consistent with the direction of most people’s dominant hand. What methods can help prevent color blindness from driving? Fixed positioning, changing traffic light brightness, and adding blue to green.
Why do some lights flash while others don’t? Lights that indicate traffic flow don’t need to flash; lights that warn drivers of traffic ahead need to flash.
Why does flashing attract attention? Colors are more easily recognized in the central field of vision, but less so in the peripheral field of vision. Motion information, such as flashing, is more easily recognized and faster in the peripheral field of vision, attracting greater attention.
For many years, Qixiang traffic lights have been widely used in various scenarios, including urban arterial roads, highways, campuses, and scenic spots, thanks to their stable performance, long lifespan, and excellent adaptability, earning them unanimous recognition from customers. We welcome your interest and are happy to contact us.
Post time: Aug-12-2025
