In 1868, the first traffic lights appeared. They were outside the Houses of Parliament and looked like railway signals. Unfortunately, the gas lanterns used to light the signals exploded a few weeks after installation. Needless to say, LED traffic lights don’t have this problem.
Incandescent traffic lights
Electric traffic signals date from 1912. They originally used incandescent lighting; in fact, many UK traffic signals still have 50-watt incandescent bulbs. These bulbs last just 12-18 months compared to five years for LEDs.
The UK’s 420,000 traffic and pedestrian signal incandescent bulbs need 100 million kWh of electricity to power them each year. This amount of electricity produces 57,000 tonnes of carbon dioxide emissions.
A similar situation exists outside the UK. In some countries, traffic signal incandescent bulbs are 100 watts or more, causing even greater energy use and pollution. It’s no wonder traffic authorities are turning to LEDs.
LED traffic lights
LEDs first came to road junctions in the early years of the 21st century. Because the LED bulbs use around 17 watts of power, they cut carbon dioxide emissions and save money.
An award-winning traffic light scheme in Brazil proves this point. The project in the city of Guarulhos has reduced the yearly municipal energy bill by £150,000. It has also cut energy consumption by 1340 megawatts. By using LEDs, the city saves enough power for more than 500 homes.
LEDs help colour-blind drivers
A Japanese scientist has taken LED technology even further. Professor Taro Ochiai has developed traffic lights with LEDs suitable for ordinary and colour-blind drivers. Ordinary motorists notice little difference in the lights, while the 10% of motorists who are colour-blind can distinguish “stop” from “go”.
The benefits of LEDs at the roadside
LED traffic signals are cheaper to run, environmentally friendly, and can help colour-blind drivers. It’s just a matter of time before LEDs are at every road junction and crossing.