Citation

Grime G. Highw. Res. Board bull. 1954; 89: 1-6.

Copyright

(Copyright © 1954, National Research Council (U.S.A.), Highway Research Board)

DOI

unavailable

PMID

unavailable

Abstract

A method of comparing vehicle headlights is described in which the opinions of drivers are obtained under controlled conditions on a test track. The method is intended both to supplement the usual tests in which the distances at which objects are recognized are determined and to replace road trials, where many conditions are uncontrolled. Tests with headlamps providing passing beams of four different types are also described. On both wet and dry roads, a pair of new british twin-dipping headlamps was preferred to other lamps tested, although a pair of lamps of a continental make was almost as well liked. Assessments of glare indicated that it was judged to be higher on wet roads than on dry ones, and that a glaring intensity of 400 to 500 candelas from each of the headlamps was easily tolerated on dry roads. Suggestions are made for further investigations of glare on dry and wet roads.