Visual performance and safety benefits of adaptive driving beam headlighting systems.

PDFTech ReportTLA 2016-01HeadlampsVisibilityGlareIn vehicle sensorsAdaptive controlHighway safetyPhotometryUnited StatesRensselaer Polytechnic Institute. Lighting Research CenterBullough, John D.Skinner, Nicholas P.Plummer, Timothy T.Rensselaer Polytechnic Institute. Lighting Research CenterTransportation Lighting AllianceUS Transportation CollectionRecent developments in solid-state lighting, sensor and control technologies are making newconfigurations for vehicle forward lighting feasible. Building on systems that automatically switch fromhigh- to low-beam headlights in the presence of oncoming vehicles, adaptive driving beam (ADB) systemscan detect both oncoming headlights and preceding taillights and reduce their intensity only in thedirection of the other lights while maintaining higher levels of illumination throughout the remainder ofthe field of view. The nominal benefit of ADB systems is the provision of high-beam levels of illuminationin the forward scene while reducing glare to oncoming and preceding drivers, who perceive low-beamillumination levels. Two dynamic field experiments were conducted; one experiment measured the abilityof observers to identify the walking direction of roadside pedestrian targets with and without using theADB system, and the other experiment evaluated the discomfort glare elicited by the ADB system incomparison to conventional low- and high-beam headlights. The findings from both experiments areconsistent with previous analytical and static field tests and suggest that ADB systems can offer safetybenefits compared to conventional headlight systems. Despite these potential benefits, ADB systems arenot presently defined in North American headlighting standards. Field measurements of the photometricperformance of an adaptive driving bean system were made in response to simulated headlight and taillight conditions. Roadway geometries were varied and multiple measurements for many conditions weremade to assess repeatability of measurements. The results of the testing are summarized in the context ofvalidating the likely safety impacts of these systems and of providing recommendations for standardizedmeasurement conditions to ensure reliabilit