Citation

Roper VJ. Highw. Res. Board bull. 1948; 11: 30-36.

Copyright

(Copyright © 1948, National Research Council (U.S.A.), Highway Research Board)

DOI

unavailable

PMID

unavailable

Abstract

Sealed-beam lighting and polarized headlighting systems are described. If all cars have polarized headlighting of the type developed cooperatively by the automotive industry, the Polaroid Corporation, and the General Electric Company, the clear road seeing distance from the analyzer, and the observer-driver is the same as that for the sealed-beam upper beam. A comprehensive series of tests were made with sealed-beam headlamps facing sealed-beam headlamps under conditions of proper and improper usage. These test results lead to a general conclusion that the range of seeing distances encountered during the period of transition to polarized head-lighting would be no greater than the range of seeing distance encountered during the present period of transition from pre-sealed beam to sealed beam head-lighting. The driver of the polarized car would enjoy somewhat higher seeing distance even during the early stages of the transition period. Compulsory legislation would be necessary, similar to that requiring safety glass.