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原文传递 LED Traffic Signal Management System. Final Report 563. Tech Summary.

题名：	LED Traffic Signal Management System. Final Report 563. Tech Summary.
作者：	Courville, L. S. F.
关键词：	Traffic signal management, Light emitting diode (LED) devices, Motorist safety, Luminous intensity, Signal modulations, Lifetime curves, Reliability, Replacement schedules
摘要：	The light source of a signal module is comprised of an array of multiple individual light emitting diodes (LEDs). Fading of the array over its operational life is a serious concern of traffi c engineers throughout the nation. The Institute of Transportation Engineers (ITE) developed minimum luminous intensity standards for LED signal modules that vary depending on the angle of the driver’s view. There are approximately 3,350 Louisiana intersections that utilize more than 100,000 LED traffi c signal modules. The Louisiana Department of Transportation and Development (DOTD) is considering a replacement schedule based on signal module lifecycle curves. These curves can show the time duration it takes for the luminous intensity of the traffi c signal modules to reduce from the initial value to the ITE minimum luminous intensity, below which it will be necessary to replace the traffi c signal modules. As such, these curves represent the safe range of operation between the initial luminous intensity and ITE minimum luminous intensity. The research objectives were to develop lifecycle curves of DOTD-approved LED traffi c signal modules and to evaluate the eff ectiveness of the two handheld devices used to measure luminous intensity by comparison to independent lab measurements. The eff ectiveness of the handheld devices needed to be assessed to determine if that device produced repeatable measurements (precision). Validating the handheld readings with lab measurements was needed to confi rm accuracy
总页数：	Courville, L. S. F.
报告类型：	科技报告