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dc.contributor.authorSivak, Michaelen_US
dc.contributorSchoettle, B.en_US
dc.contributorFlannagan, M. J.en_US
dc.date.accessioned2007-06-20T17:25:43Z
dc.date.available2007-06-20T17:25:43Z
dc.date.issued2003
dc.identifier97498en_US
dc.identifier.otherUMTRI-2003-39en_US
dc.identifier.otherPB2004-101687en_US
dc.identifier.urihttps://hdl.handle.net/2027.42/55192
dc.description"November 2003."en_US
dc.descriptionIncludes bibliographical references (leaves 18-19)en_US
dc.description.abstractBecause of rapid improvements in the light output of light-emitting diodes (LEDs), serious consideration is being given to using LEDs as light sources for headlamps. This study examined the potential effects of LEDs on discomfort glare for oncoming drivers and on color rendering of retroreflective traffic materials. In both cases, the effects of LED light sources were compared to the changes in these properties that occurred when the traditional tungsten-halogen light sources were replaced with high-intensity discharge (HID) light sources. Specifically, the effect on discomfort glare was estimated by comparing the chromaticities of 7 LED light sources (considered for use in headlamps) with the chromaticities of the light sources from 17 actual HID headlamps. Analogously, the effects on color rendering were estimated by comparing the chromaticities of 46 retroreflective materials when illuminated by the LED light sources with the chromaticities of the same materials when illuminated by the HID light sources. The main findings concerning the range of LEDs that are currently being considered for use in headlamps are as follows: (1) Headlamps using LEDs with the chromaticities examined here are predicted to lead to more discomfort glare than the current HID headlamps, and substantially more discomfort than tungsten-halogen headlamps. Keeping the correlated color temperature as low as practicable is likely to minimize the problem. However, the relationship between spectral power distribution and discomfort glare is not fully understood, and further research on this issue would be valuable. (2) Color rendering with headlamps using the LEDs examined here is likely to be acceptable. (3) The spectral power distributions of headlamps using the LEDs examined here will not have appreciable effects on the relative brightness of colored retroreflective materials.en_US
dc.description.sponsorshipMichigan University, Ann Arbor, Industry Affiliation Program for Human Factors in Transportation Safetyen_US
dc.formatill. (some col.)en_US
dc.format.extent23en_US
dc.format.extent701151 bytes
dc.format.mimetypeapplication/pdf
dc.languageEnglishen_US
dc.publisherUniversity of Michigan, Ann Arbor, Transportation Research Instituteen_US
dc.subject.otherGlare/ Dazzleen_US
dc.subject.otherLighting Componentsen_US
dc.subject.otherHeadlampsen_US
dc.subject.otherColor/ Chromaticityen_US
dc.subject.otherReflectance/ Absorptivity/ Reflectivityen_US
dc.subject.otherTraffic Control Devicesen_US
dc.subject.otherOncoming Trafficen_US
dc.subject.otherDrivers/ Vehicle Operatorsen_US
dc.subject.otherHuman Comfort/ Discomforten_US
dc.subject.otherOptical Spectrumen_US
dc.subject.otherLED Headlampsen_US
dc.subject.otherHID Headlampsen_US
dc.titleLED headlamps: glare and color renderingen_US
dc.typeTechnical Reporten_US
dc.subject.hlbsecondlevelTransportation
dc.subject.hlbtoplevelEngineering
dc.description.bitstreamurlhttp://deepblue.lib.umich.edu/bitstream/2027.42/55192/1/UMTRI-2003-39.pdfen_US
dc.owningcollnameTransportation Research Institute (UMTRI)


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