Citation

Hunt JH. Highw. Res. Board bull. 1948; 11: 21-29.

Copyright

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

DOI

unavailable

PMID

unavailable

Abstract

A review is presented of a study sponsored by the automobile manufacturers association with the cooperation of the polaroid corporation and the general electric company in the development of a system to utilize the advantages of polarized headlighting. Essential components of the polarized light system are the viewer and the polarized headlamps. This work was undertaken because polarized headlighting can practically eliminate glare when cars meet at night if all the cars involved are properly equipped. The polarized headlamps are 125 watt all glass units with a polarizing sheet protected by glass mounted on the front of the flat lens. The viewer is used to stop the polarized light from the meeting cars. It must transmit enough of the reflected light from the roadway, which originated in the car's own lamps, so that adequate vision is obtained. A very thin sheet of polaroid, protected by highly transparent plastic is supported in a light metal frame. This frame is supported by linkage from the windshield frame in such a way that the plane of polarization can be adjusted to be perpendicular to the plane of polarization of the meeting headlamps. Windshields must be so manufactured and inspected as to eliminate faults not apparent in ordinary light. At night when all cars use this system, the driver can see almost as well during the time of passing as he can see with the viewer in place with no opposing traffic. Present legal requirements for headlamps must be changed in each state before the polarized light system can be used. Recommendations are made for the adoption of a complete polarized headlighting system.