Target Detection Distances and Driver Performance with Swiveling HID Headlamps 2004-01-2258

Twent-two participants of varying ages detected roadside targets in two consecutive dynamic evaluations of a horizontally swiveling headlamp vehicle and a vehicle with the same headlamps that did not swivel. Participants detected targets as they drove unlighted low-speed public roads. Scenarios encountered were intersection turns, and curves with approximate radii of 70-90m, 120-140m, 170-190m, and 215-220m. Results from the first study found improved detection distances from the swiveling headlamps in left curves, but unexpectedly decreased detection distances in larger radius right hand curves. The swiveling algorithm was altered for the second study, and the headlamps used did not have the same beam pattern as in the first study. Results from the second study again found improved detection distances from the swiveling headlamps while in the larger radius right hand curves fixed and swivel were not statistically different. No practically significant results were found as regards driving performance measures taken in these studies. These study results suggest that horizontally swiveling headlamps can provide for increased detection distances in many curve and turn scenarios; however, care must be taken in the execution of a swiveling algorithm and beam pattern.