Citation

Vaswani NK. Transp. Res. Rec. 1977; 628: 52-56.

Copyright

(Copyright © 1977, Transportation Research Board, National Research Council, National Academy of Sciences USA, Publisher SAGE Publishing)

DOI

unavailable

PMID

unavailable

Abstract

Through selected case studies, this paper illustrates the way in which the inadequate visibility of road signs and pavement markings at night contributes to wrong-way driving. A concept termed the keg of legibility, which delineates the limits of nighttime visibility under low-beam headlights, is described. The application of the keg-of-legibility concept to the placement of signs, markings, and additional devices that help guide the motorist through the intersection of a four-lane divided highway and another road is discussed. Examples of wrong-way entry on roads having poor geometrics are used to emphasize the need for such guidance.