Citation

Larimer EM. Highw. Res. Board bull. 1957; 163: 27-32.

Copyright

(Copyright © 1957, National Research Council (U.S.A.), Highway Research Board)

DOI

unavailable

PMID

unavailable

Abstract

Studies by the national safety council have established that peril to life and vehicle trebles after sunset, primarily as a result of reduced visibility. Low illumination, contrast extremes, atmospheric conditions, and attendant driver reaction at day's end contribute a host of physical and sensible limitations. Other statistics show that rear-end collisions are the largest single factor in motor vehicle accidents. In spite of very considerable and progressive efforts of the automobile industry and enforcement agencies, unlighted, over-aged, damaged, or improperly maintained or equipped vehicles are a continuing hazard to the motorist and a constant challenge to safety leaders. The reflectorized license plate offers a universal opportunity and practical enforcement device for maintenance of minimum protection. This paper presents data to establish typical visibility distances of unlighted vehicles, both with and without reflectorized license plates, relative to safe stopping distances. Visibility and performance limitations imposed by rain, mist, snow and glare have been considered in establishing performance criteria, because 25 percent of all accidents occur under such conditions. Observations indicate that a completed plate capable of reflecting 5 c.P. Per incident foot-candle provides the minimum brilliance for requisite warning in typical situations. Practical considerations include ease of cleaning, damage resistance, and effective performance although bent or mutilated. The experience of several states has shown that such reflectorized license plates have aided enforcement agencies. Legibility distance from the rear is markedly improved and the front license plate of lighted vehicles is both visible and legible to the motorist approaching from the opposite direction. This feature assures positive delineation of one-eyed vehicles and location of parked cars prevalent in residential areas.