Citation

Bhise VD, Farber EI, McMahan PB. Transp. Res. Rec. 1976; 611: 1-16.

Copyright

(Copyright © 1976, Transportation Research Board, National Research Council, National Academy of Sciences USA, Publisher SAGE Publishing)

DOI

unavailable

PMID

unavailable

Abstract

This paper presents results of field research conducted to study the applicability of laboratory threshold visibility data in predicting seeing distances to stand-up and road-surface by use of different headlight beam patterns. A vehicle equipped with a precision odometer system was used to measure detection distances of 12 subjects under different target-background-glare conditions. The subject testing was followed by extensive photometry to measure the only on an origin area, & that the spatial aggregation bias condition. The reflectance properties of the pavement and road shoulder were also mapped. Detection distances were predicted from directly measured brightness and brightness computed from target and background reflectance data, ambient brightness, and assumed head-lamp beam patterns. A comparison of field observed and predicted seeing distances showed good to excellent agreement. The necessary contrast multipliers needed to account for factors such as complexity of road surface delineation and transient adapatation are also discussed.