What is traffic light and its function

Traffic lights, also known as traffic signals, traffic lamps, traffic semaphore, signal lights, stop lights, robots (in South Africa), and traffic control signals (in technical parlance) are signaling devices positioned at road intersections, pedestrian crossings, and other locations to control flows of traffic. Traffic light is a safety device that appear on the road in vast majority of country in the world. Traffic lights are an important element of traffic safety management to maintain safety on road for pedestrians and drivers. Increasing accidents and fatalities have driven the growth of the traffic lights market, as traffic lights provide drivers control on road and improve the flow of traffic. Another factor that has driven the growth of the market is the improvement in traffic flow regulations by traffic safety organizations by constantly upgrading and maintaining them and creating various pedestrian facilities, extra street lighting, traffic signal modifications, and signage marking improvements. The normal function of traffic lights requires sophisticated control and coordination to ensure that traffic moves as smoothly and safely as possible and that pedestrians are protected when they cross the roads.

Traffic light color meaning

There are 3 most frequently color that we can see on the traffic light. The 4 color are red, green and orange. Red color in the traffic light is to alert the driver to stop their car. Orange color in the traffic light is to alert the driver to proceed with caution. Green color is to tell driver to go.


An electric traffic light was developed in 1912 by Lester Wire, a policeman in Salt Lake CityUtah, who also used red-green lights. On 5 August 1914, the American Traffic Signal Company installed a traffic signal system on the corner of East 105th Street and Euclid Avenue in ClevelandOhio It had two colors, red and green, and a buzzer, based on the design of James Hoge, to provide a warning for color changes installed outside the Houses of Parliament in London to control the traffic in Bridge Street, Great George Street and Parliament Street.  The first three-color traffic light was created by police officer William Potts in DetroitMichigan in 1920. In 1922 traffic towers were beginning to be controlled by automatic timers.

LED Traffic Light

With LED comprehensively in the mainstream, the next fourier in traffic light is control.Call it smart, call it connected, call it what you like – the point is that your traffic lights can be controlled. Dimmers and sensors have been around for donkey’s years, but the challenge now is to make them more sophisticated, get them to communicate with other devices and make sure people use them.After smart grids, smart sewage and smart lights, here comes the smart traffic lights.To be fair, many lights already have some sensors and can adjust their cycles based on feedback from the road, but what I’m talking about here is on a whole other level. BMW and Siemens unveiled a system of networked traffic lights that can communicate with nearby cars to warn them about road conditions, help them better use anti-idling features, but that can also learn about traffic patterns from those cars and adjust cycling times to optimize traffic flow, saving time and fuel

New trend traffic light

The low energy consumption of LED lights can pose a driving risk in some areas during winter. Unlike incandescent and halogen bulbs, which generally get hot enough to melt away any snow that may settle on individual lights, Beside that, engineers have managed to reduce the average power consumption of a traffic signal – red, yellow, green – to just one to two watts. For traffic lights based on incandescent bulbs, this value amounts to around 60 watt. The new traffic light, which is based on highly efficient LED and digital modules, is expected to benefit city budgets as well as the environment thanks to the enormous energy savings. To achieve such the new 1-watt-technology – branded as Sitraffic One – is already in use in pilot projects in Bozen, Italy and in Bietigheim-Bissingen, in southern Germany. Conventional incandescent bulbs behind colored diffusion disks are still in operation in many traffic lights around the world. Converting these to the new 1-watt technology reduces power consumption by up to 98 percent. Cities can cash in enormously by replacing incandescent bulbs with 1watt-technology. After as little as five years, a converted intersection begins paying for itself. Even updating conventional 230-volt LED technology pays off: at an average intersection with about 55 signal lights, the new 1-watt signals can save about 1,600 kilowatt-hours per year and reduce carbon emissions by about 960 kilograms.