Abstract
This report provides updated information regarding the market-weighted prevalence of various headlamp design attributes in the U.S. and a summary of recent trends for these design attributes. The main findings were as follows: (1) there was a general transition from dual-filament light sources in 1997 to single-filament sources in 2007; (2) the preferred optics changed from lens-based in 1997 to mostly reflector-based optics in 2007; and (3) while mechanical aim was the most frequently specified aiming method in 1997, the 2007 sample made nearly exclusive use of visual/optical aiming (with visual/optical right side as the most common specific type). (Author/publisher)