Perceived discomfort glare from an adaptive driving beam headlight system compared with three low beam lighting configurations

2015

Adaptive driving beams (ADB) avoid glare for approaching or leading drivers but otherwise provide high beam lighting. Audi's implementation uses a matrix of LED units to deactivate individual LEDs when it detects leading or approaching vehicles. A test track study measured perceived discomfort glare by having 20 participants view and rate headlight configurations from five roadway approaches. The headlight conditions included an Audi A8 with ADB, the A8 with ADB deactivated (resulting in an LED low beam pattern that met European specifications), a 2013 Mazda 3 with low beam adaptive curve HID headlights, and a 2014 Dodge Durango SUV with low beam HID headlights. Five approaches included left and right gradual and sharp curves and a straight approach. Participants rated glare comfort on a scale from 1 to 9, with higher ratings indicating more acceptable glare. Glare from the Durango was rated as less comfortable (M = 6.15) than the other three systems. The Mazda 3 (M = 6.82) received more acceptable glare ratings than the Durango. The A8 ADB (M = 7.25) received more acceptable glare ratings than the Durango and the Mazda 3 but was not rated differently from the A8 low beam LED condition (M = 7.36). Mean and maximum illuminance measures for the approach vehicles corresponded well with subjective ratings. These findings demonstrate the promise for adaptive driving beam headlight systems, and the tested adaptive driving beam system is presently available for use in the European market. However, FMVSS 108 requires discrete high and low beam settings, which does not allow adaptive driving beam systems in the United States. Measuring illuminance dynamically may provide an alternative regulatory approach.