The study developed by Rensselaer Polytechnic Institute with John Bullough as investigator explores the photometric requirements, measurement, and maintenance of traffic signal modules using light emitting diodes (LEDs).
The final report documents and presents the results from a study of the photometric requirements, measurement and maintenance of traffic signal modules using light emitting diodes (LEDs). Differences between LED technology and the incandescent lamps used in previous traffic signal modules in terms of photometric performance, color, and failure modes require new approaches to traffic signal maintenance. Findings from a review of literature on human factors and maintenance practices, from a series of laboratory and field measurements of LED traffic signal modules, and from an analysis of the failure mechanisms of traffic signal modules provided by several different transportation agencies, are provided. Based upon these findings and upon an economic analysis with different assumptions regarding LED traffic signal.
The report was just published by the Transportation Research Board, through the National Cooperative Highway.
It is available online at: http://www.trb.org/Publications/Public/Blurbs/Replacement_Processes_for_
Light_Emitting_Diode_LED_162334.aspx
