AbstractsPhysics

"Traffic lights using state-of-the-art LED illumination use 90 percent less electricity and offer a much longer service life and durability than their incandescent counterparts. Taking advantage of the countless benefits, cities around the country have been replacing traditional filament-based traffic signal bulbs with LEDs for years. However, the degradation of LEDs and hence the replacement strategy, are a concern which is faced by most of the Departments of Transportation. The thesis work sponsored by MoDOT, presents the replacement strategy developed based on the field study of LED indicators in Missouri. Three types of analysis are performed with multiple data point collection - Intensity analysis, manufacturer analysis and temperature analysis. This thesis is an effort to provide decision support for MoDOT regarding the prudent choice of manufacturer, with regards to temperature dependency. Along with the extension of 2010 study at Missouri University of Science and Technology, the work presented also addresses the unresolved issue about performance of red lights and improves the intensity analysis method." – Abstract, page iii.