Functions, History and Reasons for Color Sorting

Jakarta, IDN Times – In your daily activities, you must have met a traffic light several times or what is also known as a ‘red light’.

Traffic lights that we know do have 3 lights with different colors, namely red, yellow, and green. Of each of these colors, there are traffic light meaning this one. Check out more information about the following red lights, starting from red light function, red light historyand means.

Also read: 3 Tips When Stopping at a Red Light

1. Traffic light function

Red Light: Function, History and Why These 3 Colors Control TrafficDock. Personal

This red traffic light is usually found at the intersection, red light function The main thing is to avoid congestion and control the flow of traffic. Because motorcyclists and car drivers know when to take turns crossing intersections.

The red traffic light means stop or stop, yellow means you have to slow down, and green means you can pass. Not only that, traffic lights also help pedestrians to cross the road in zebra crossing with safe.

Also Read: 7 Facts about Traffic Light Transformation that Help Road Users

2. The first traffic light was invented in England

Red Light: Function, History and Why These 3 Colors Control TrafficThe world’s first traffic light (

Go directly to red light history, this traffic light was first installed in London, England, on December 9, 1868 ago. At that time, traffic lights were not only intended for motorized vehicles, but also for pedestrians and horse-drawn carriages.

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Because at that time pedestrians and horse-drawn carriages filled the streets of London. That’s why John Peake Knight, a railroad manager, took the initiative to adapt the rail method to control traffic.

The train method in question is to use a semaphore or signal pole with a small arm that gives a sign whether the train can pass or not. In this adaptation, John Peake Knight’s semaphores will signal “stop” and “go” during the day, while at night red and green gas lights will illuminate the sign.

After that, the traffic light has continued to develop until now, which is very sophisticated because it is equipped with a camera CCTV as well as the remaining time display screen.

Also Read: Irony! These cool motorbikes are even injected dead

3. The reason traffic lights use red, yellow, and green colors

Red Light: Function, History and Why These 3 Colors Control Traffic(doc. Gettyimage/Ernst Haas)

You may be wondering why traffic lights use red, yellow, and green. Why not use other colors like purple, brown, or blue for example? It turns out there the reason for using the red lightyellow and green, you know!

The color red was chosen because it is a symbol of danger for many cultures, which makes sense, since red has the longest wavelength on the spectrum. That way it can be seen from a greater distance than other colors.

Meanwhile, yellow was chosen because it has the longest wavelength in the spectrum, second only to red. That’s why the yellow color is also chosen for various warnings, such as crossing zones, school zones, and other warnings.

Finally, green, this color actually changes function over time. In the past, green was used in the rail system to mean “be careful”. But finally the green color changed to mean “go” or may go.

Green is also one of the most visible colors besides red and yellow.