The simple traffic light, which was first introduced in the UK in 1868 to control the traffic outside the Houses of Parliament in London, has undergone many changes in its lifetime, the most notable of which is the departure from the use of standard incandescent lamps to LED lighting. It is still the case that conventional light bulbs are used in the majority of traffic lights but more and more local authorities are now weighing up the relative costs and reaching the conclusion that LED traffic light signals can represent real savings for their council tax payers.
We set out below the technology behind LED traffic lights and highlight the ways that this technology can improve upon the traditional type of traffic signal.
The Technology
When a light emitting diode (LED) is used as a source of lighting, the lifetime of the lamp is many times greater than that of one with a standard incandescent or fluorescent light source. LED lamps are made up hundreds of tiny, electronic lights, around the size of the head of a pencil.
In addition to their longevity, LEDs are becoming increasingly popular because of their relative energy efficiency, the brightness of the light that they give out and the massive cost savings that converting to LED technology can lead to.
In some respects, the UK is lagging behind other European countries and the USA and Canada, who, in recognition of the real advantages of LED lighting, are implementing (or have already completed) a wholesale change from traditional traffic lighting to LED traffic light signals.
The reasons for this departure from traditional incandescent lamps in traffic signals are fourfold and we set them out below.
The Benefits of LED Traffic Light Technology
Energy Saving
One of the major advantages of LED traffic signals is that they are extremely energy efficient. This is important for two main reasons.
Firstly, the more energy that is used in powering a set of traffic lights, the greater is the demand for electricity. This has an obvious effect on the cost of powering the lights, which, when multiplied by the number of traffic lights in a major city, can result in substantial amounts of money. It has been estimated that for some of the larger cities, the introduction of LED traffic signals could result in a saving of almost £1,000,000 every year.
Secondly, reducing energy consumption has environmental benefits, an important commodity at a time when we are all mindful of the harmful effects of carbon emissions and the need to take every possible measure to preserve the sustainability of the planet.
Quality of Lighting
It is a widely held belief that the quality of the light produced by a LED traffic signal is greater than that of a traditional lamp. Furthermore because of the technology behind the LED traffic signal, the light has an equal brightness over the entire surface of the lamp.
Cost
We have already considered the cost implication of having to replace traditional lamps in traffic signal far more frequently than in LED traffic signals. However, there are other, indirect costs that also need to be taken into account. Because incandescent lamps may last for only a matter of months (compared to years for LED lamps) they have to be replaced frequently. This involves a considerable number of hours every year, with local authorities having to employ an entire workforce simply to maintain their complement of traffic signals.
Convenience
Nothing is more annoying than sitting in a traffic queue because a set of traffic lights has broken down due to an expended lamp. It goes without saying that the shorter the life of the lamp, the more often this is going to happen. The LED traffic signal reduces these occurrences to a minimum because of its durability.
Summary
The development of the technology behind LED traffic signals represents an opportunity for local authorities to make real money savings whilst also benefiting the environment. It is to be hoped that they make a real commitment to moving towards the replacement of all traditional traffic signal with those that are sourced by LED.
