Citation

Roper VJ. Highw. Res. Board bull. 1958; 191: 49-52.

Copyright

(Copyright © 1958, National Research Council (U.S.A.), Highway Research Board)

DOI

unavailable

PMID

unavailable

Abstract

Dynamic tests were conducted of the night driving situation using observer-drivers. Test methods are described although it is concluded that a dynamic test of this kind is still not fully representative of a typical driving situation. Part of the variance is that observer-drivers knowingly engaged in a test, and therefore they were paying more attention than would the normal driver. The importance of proper headlight aiming is emphasized. Two recent improvements have recently been made by manufacturers: Improved sealed beam lamps installed on 1956 cars, and the dual-unit system. A considerable increase in seeing distance can be accomplished by having headlights aimed exactly right. All sealed beam headlights are now manufactured with three aiming pads on the front surface of the lens. The front surfaces of these pads are correctly aligned with respect to the aim of the beam. This permits the use of simple, inexpensive mechanical aimers to seat on the front surfaces of these pads and to align the lamps correctly without the need for a darkened area.