AIDC project number: RR10.1
Richard Wies (UAF)
ADOT&PF has a specific research need for evaluating the level and quality of light produced from LED based street lighting to determine if it meets AASHTO national highway visibility and traffic safety standards at the reduced power levels recommended by LED streetlight manufacturers. To address this need, the UAF team, lead by Professor Richard Wies, will focus specifically on comparing LED street lights to the typical HPS street lights in terms of: light intensity (lumens, foot-candles) at various points along a rectangular ground grid (the grid should cover at least 4 times the light mounting height down the road from the light and 2 times the mounting height across the road and 1 times the mounting height on the sidewalk side, for a total of 3 times the mounting heights across the road). visible light spectrum (color) using a photometer. This information is pertinent to evaluation of color perception and psychological impacts under LED light. Researchers at the UAF Department of Biology and Wildlife and Department of Psychology studying the effects of narrows spectrum LED lighting for plant growth and the effects of narrow spectrum LED lighting on seasonal effective disorder are interested in the results of this work. Visual (quality) observation of the illuminated surface for each light using a high Mpixel digital camera at a constant exposure level and shutter speed set based on the highest level of light (250W HPS). energy consumption (watts) with a wattmete. Streetlights to be compared include 150 and 250 watt HPS fixtures and the LED fixtures that LED manufacturers claim provide equivalent output. When the light intensity has been measured, that information will be used to determine whether typical existing HPS lighting systems retrofitted with equivalent LED fixtures will meet AASHTO standards. The typical lighting arrangements will include two of the most common lighting layouts (mounting height, spacing, lateral offset, etc) found in the lighting systems the city of Fairbanks is planning to retrofit with LED streetlights. We will also do a literature search of previous testing results and past experiences with visual monitoring and physical measurements of LED street lighting technology. The majority of funds will support a graduate student who will be involved in all task activities.