Citation

Shelby MD, Tutt PR. Highw. Res. Board bull. 1958; 170: 24-50.

Copyright

(Copyright © 1958, National Research Council (U.S.A.), Highway Research Board)

DOI

unavailable

PMID

unavailable

Abstract

Speed and placement by vehicle type, maneuver, and condition were studied on 2-lane rural highways, rural bridges, and particularly the effects on traffic behavior of a vehicle stopped on the shoulder of a freeway overpass. Speed was apparently not a factor in the elements studied. Drivers are apparently influenced in their lateral placement more by the edge of the pavement than by the centerline of the road. Shoulder width did not appear to affect the lateral placement of vehicles. The type of shoulder had a definite effect on the lateral placement of vehicles. The higher the quality of construction, the closer to the shoulder traffic will drive. Lateral placement appears to be a function of lane width. Vehicle encroachment across the centerline and on the shoulder is a definite problem. Bridge width was found to have a definite influence on lateral placement of vehicles. The presence of the stopped vehicle on the 6-foot bridge shoulder did have an effect on traffic, but as traffic volumes increased the effect decreased. The presence of the vehicle did not seriously decrease the capacity or noticeably impair the safety of the facility. Differences in behavior in both speed and lateral placement were detected, with the lateral placement being most noticeably affected.