Overview
The primary objective of this research was to identify significant environmental (i.e., weather) variables that may contribute to snow and ice buildup on LED traffic signal lenses. If a subset of variables can be identified that may predict the potential occurrence of snow and/or ice buildup on LED traffic signal lenses, then it may be possible for traffic engineers to take a more proactive approach to eliminating or minimizing the potential negative effects.
One of the unintended consequences of the transition to LED traffic signals lenses/indications is the fact that LEDs do not produce heat to the traffic signal lens or face of the traffic signal display. Therefore, LEDs do not provide a “melting” element to traffic signals in the northern climates that experience snow and ice conditions.
The U.S. Department of Transportation (USDOT) has worked with ITE in determining the issues related to the snow and ice conditions on LED traffic signal lenses. ITE and USDOT conducted a stakeholder workshop on December 14–15, 2010 that created a set of proceedings documenting the issues, findings, and potential next steps in addressing the snow and ice-covered LED traffic signal lens issue. One of the outcomes of the workshop was the initiation of a small research task to further explore the environmental conditions (i.e., weather) upon which the snow and ice problem occurs. This report summarizes the research effort completed to fulfill that outcome.