Discomfort Glare Ratings of Swiveling HID Headlamps

Sixteen participants aged 55–65yrs provided deBoer scale ratings of discomfort glare for a vehicle with horizontally swiveling HID headlamps and a vehicle with the same headlamps that did not swivel in eight scenarios staged in a darkened parking lot. Participants, who were seated in the driver’s position of a stationary vehicle and instructed when to look, viewed the oncoming test vehicles in scenarios of 180m left turn, 180m right turn, 80m left turn, 80m right turn, left turn beside participant vehicle, crossing left in front of participant vehicle, right turn beside participant vehicle, and straightaway, in counterbalanced presentation orders. The swiveling headlamp vehicle provided statistically lower glare ratings in both 180m curves and the 80m right curve and statistically lower or similar in the intersection scenarios than the fixed headlamp vehicle. The fixed headlamp vehicle provided statistically lower glare ratings in the 80m left curve; however the mean glare rating for the swiveling headlamp vehicle in this scenario was better than “Satisfactory” on the scale. The results of this study suggest that this execution of swiveling headlamps, as compared to fixed headlamps, provides equivalent or reduced discomfort glare to other drivers in almost all approach scenarios tested.