Citation

Roberts RR. Transp. Res. Rec. 1976; 601: 73-75.

Copyright

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

DOI

unavailable

PMID

unavailable

Abstract

A before and after field study was carried out to evaluate the effects of providing full width shoulders across long-span bridge structures as a means of improving traffic and safety. This study was carried out in two major stages. The first stage consisted of studying the effect of various bridge shoulder curb widths on the operational characteristics of vehicles on the bridge. The second stage consisted of making these same studies on the effects of various bridge shoulder curb widths with a guardrail type of barrier flush with the face of the curb and offset 2 ft. from the face of the curb. The following conclusions were reached after the results of the study were evaluated: Vehicle speed and placement data may be combined for different days of the week without any major loss of information; Relative location had a significant effect on speeds as the vehicles moved through the test sections; All curb conditions had a significant effect on vehicular speeds; There is significant interaction between positions and conditions and conditions for vehicle placements; Vehicles travel farther from the roadway edge at the center of the bridge under all curbing conditions; Vehicles travel farther from the shoulder at the center and the upstream and downstream ends of the bridge; With the 6 ft. curb, vehicles tend to move slightly away from the shoulder edge as they cross the bridge, then tend to overcorrect, and move nearer the shoulder downstream of the bridge.