Citation

Garber NJ, Saito M. Transp. Res. Rec. 1984; 956: 33-36.

Copyright

(Copyright © 1984, Transportation Research Board, National Research Council, National Academy of Sciences USA, Publisher SAGE Publishing)

DOI

unavailable

PMID

unavailable

Abstract

The Virginia Department of Highways and Transportation uses a special centerline marking designated mountain pavement marking on two-lane highways in mountainous regions. This marking consists of a single broken line supplemented by PASS WITH CAUTION signs. This marking has been criticized because it does not prohibit passing on sections of highways with inadequate sight distances. Consequently, a study was conducted to determine if this marking system should be replaced with the Manual on Uniform Traffic Control Devices (MUTCD) standard marking pattern and to develop guidelines for minimum lengths of passing zones and minimum sight distances for safe passes on two-lane mountain roads. In this paper the results of that part of the study that dealt with the development of minimum passing criteria are presented. Passing maneuvers were recorded at five sites with a 16-mm movie camera. Relevant data were then extracted from the film and used to develop a regression model for the minimum length of passing zone based on the passing speed and the difference in speeds of the passing and impeding vehicles. A minimum passing sight distance for a safe pass or a comfortable aborting of the pass was then developed using the concepts of critical position and comfortable deceleration. The results indicate that the minimum values suggested in the MUTCD are inadequate and that there are no significant differences in traffic characteristics between roads with the special marking and those with standard MUTCD marking. The results also indicate that, although speed is the major factor affecting the passing distance on two-lane highways in mountainous regions, other factors such as the difference between the speeds of the passing and impeding vehicles and grade, in that order, also have some effect.

Language: en

Keywords

HIGHWAY SIGNS, SIGNALS AND MARKINGS; ACCIDENT PREVENTION - Control; VISIBILITY - Measurements