Published in 1977
Through selected case studies, this report illustrates how the inadequate visibility of road signs and pavement markings at night contributes to wrong-way driving. A concept termed "keg of legibility" for visibility at night has been developed by the author to delineate the limits of night visibility under low beam headlights. The report discusses the application of the keg of legibility to the placement of signs, markings, and additional devices that can be used to help inform the motorist who is to negotiate a four-lane divided highway and to guide him through the intersection. Cases of poor road geometrics are cited to emphasize the need for such information and guidance.
Last updated: January 28, 2024