LED Light Bulb

Light-emitting diode (LED) traffic signal modules were first widely used in the 1990s. An LED signal module provides significant energy savings relative to an incandescent lamp, and the light source has a much longer service life. LEDs are now being implemented on a widespread basis and will see increased use as a result of the Energy Policy Act of 2005. There are, nevertheless, concerns regarding monitoring, maintenance, and replacement of LED signal modules. These concerns are centered on several factors. It should be noted that many of the problems associated with LED traffic signal modules were the result of early implementations. As will be discussed in more detail, the ITE standards have gone through a major revision based on early experience and the improvements in LED technology. The traffic signal head application of LED technology is still in a process of continual improvements as a result of the increasing population of installed LED traffic signal modules, longer experience, and competition for business.

Many LED signal modules were initially financed outside of the transportation agency as an energy conservation incentive. This has LED to some challenges regarding replacement. Once installed, the cost burden for replacing LED signal modules typically lies with the transportation agency. The gradual reduction of LED light output, combined with the higher costs of replacement, may lead to LED signal modules remaining in service after failing below desirable performance levels unless the owning agency has an appropriate replacement strategy.