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 important signaling devices that normally located on road intersections, T-junction, pedestrian crossings, and other locations so that it can be used to control the flows of traffic and reduce the occur of road accident. Beside that, traffic light also act as a safety device that appear on the road in vast majority of country in the world. Traffic lights are very important on the traffic safety management to maintain safety on road for all the pedestrians and drivers across the road. Increasing accidents and fatalities occur on the road have cause 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 the respective 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 operation of traffic lights requires sophisticated control and coordination to ensure that traffic flow is as smoothly and safely as possible and ensure that the safety of pedestrians and protected them when they drive or walk cross the roads.

Traffic light color meaning

There are 3 most frequently color that we can see on the traffic light in vast majority of country. The 3 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.


The first electric traffic light was developed in 1912 by Lester Wire, a policeman in Salt Lake City, Utah, there are only 2 type of color being used on the traffic light, which is the red and green. After 2 years, which is 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 Cleveland, Ohio. The new traffic light also had two colors, red and green, but it have add in some new feature, which is the new traffic light have build in a buzzer for some safety purpose. The appearance and function of this new traffic light is based on the design of James Hoge. The purpose of this new traffic light is to provide a warning for color changes and used to install outside the Houses of Parliament in London to control the traffic in Bridge Street, Great George Street and Parliament Street. After 5 years, the first three-color traffic light was created by police officer William Potts in Detroit, Michigan in 1920.

LED Traffic Light

With LED gradually comprehensively in the mainstream, the next fourier in LED traffic light is about control. Call it smart, call it connected, call it what you like – the point is that your traffic lights can be controlled. Electronic component such as the dimmers, sensors and wifi-module have been developed many years ago, but the challenge now is to make them more sophisticated, get them to communicate with other devices such as traffic light. After smart street light, smart sewage and smart lights, now is the smart traffic light. To be fair, many traffic lights already have some sensors build in and can adjust their cycles based on feedback from the road, but what I’m talking about here is on a whole other level. Technologies giants, BMW and Siemens had already developed 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, this smart networked traffic light have a lot of benefit such as it can save time and fuel of the driver, pedestrian as well as to improve the flow of traffic, so that the flow can be more smooth.

New trend traffic light

Engineers is already developed the new trend traffic light to reduce the average power consumption of a traffic signal, which is the average power consumption 3-colour street light to just one to two watts. For the conventional traffic light which is based on the incandescent bulbs, its average power consumption is around 60 watt. The new trend traffic light, with the use of highly efficient LED and digital modules, is expected to benefit city budgets as well as the environment due to its low power consumption. The new 1-watt-technology is branded as ‘Sitraffic One’ is already being introduced to the traffic system and netwok in some places, such as in Bozen, Italy and in Bietigheim-Bissingen, Germany. If replace the conventional traffic light that use incandescent bulbs to the new 1-watt 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. We can seen that the conventional traffic light that use incandescent bulbs behind colored diffusion disks are still in operation in many traffic lights around the world. By converting these to the new 1-watt technology, it can reduce power consumption on that traffic light by up to 98 percent. So, all the cities persuade for replacing the incandescent bulbs traffic light with the new 1watt-technology traffic light.