Citation

Box PC. Highw. Res. Rec. 1972; 41: 10-20.

Copyright

(Copyright © 1972, National Research Council (U.S.A.), Highway Research Board)

DOI

unavailable

PMID

unavailable

Abstract

The findings of a study of freeway accidents and illumination are reported. The time during which ambient light conditions are such that typical roadway illumination would have an effect was found to be from 15 min after sunset to 15 min before sunrise. Lighted freeways were found to have lower (better) night-day accident ratios than unlighted ones. The lighted freeways with the lowest illumination, averaging 0.6 horizontal footcandles maintained, had the best accident ratio. This corresponds to an initial illumination design level of about 1.0 hfc. A wide variation was found in average illumination between adjacent pairs of luminaires along specific freeway sections. This was found to be principally a result of differences in individual lamp output. The variations of hfc averages and uniformity are so great as to cast doubt on the real value of these elements in lighting design calculations.

Language: en

Keywords

HIGHWAY ACCIDENTS; STREET LIGHTING; ILLUMINATING ENGINEERING