Citation

Adler B, Lunenfeld H. Transp. Res. Rec. 1974; 502: 22-33.

Copyright

(Copyright © 1974, Transportation Research Board, National Research Council, National Academy of Sciences USA, Publisher SAGE Publishing)

DOI

unavailable

PMID

unavailable

Abstract

One near-term improvement for vehicle forward lighting is a 3-beam 4-head-lamp system. This system, which includes a high and low beam with increased intensities and a moderately high-intensity midbeam, should provide increased seeing distance. This paper describes the results of a 3-phase evaluation of various combinations of beam usages to achieve the 4 modes. A computer program calculated the glare in the rearview mirror as a following vehicle with different headlighting systems approached from the rear. The results show very minor difference in glare among any of the beam configurations on the same mode. Vehicles equipped with the 3-beam systems were driven by a sample of drivers under a representative sample of road and traffic conditions. An evaluation of the subjective responses of the drivers to the system was made, and objective measures of the traffic stream's responses (through dimming requests) were recorded. There were slight differences in the number of dimming requests among the various configurations, and the drivers subjectively favored the use of a mid-beam mode but were unable to select 1 high-beam system as superior. The last phase of this program was an empirical determination of seeing distances. The results of this phase showed that a beam configuration using all 4 headlamps in the high-beam mode yielded better seeing distances than others. The high-beam mode using all 4 head lamps appears to be the best configuration of those tested because it does not represent excessive glare and does not yield greater dimming requests, but does yield greater seeing distances.