00272081

Component

http://onlinepubs.trb.org...s/trr/1974/489/489-002.pdf

http://scholar.google.com...erry&publication_year=1974

This paper reports results of a field study to evaluate the effects of opposing flow on left-turn reduction factors in computing capacity of two-lane approaches to two-phase signalized intersections with no separate left-turn lanes. Time-lapse photography was used to gather data on the approaching and opposing volumes and the delaying effects of left turners. Reduction factors were computed for different numbers of left turns per cycle by using regression analysis. The two variables that explained most of the variance were the ratio of the opposing flow in the curb lane to its capacity and the ratio of the arrival time of the first left-turning car to the green-plus-yellow time. Results indicate that, when the opposing curb lane is loaded, left turns have a much greater reducing effect than that given in the Highway Capacity Manual. The capacity-reducing effect of a single left-turning vehicle is greater than the incremental reduction effect of the second, third, and fourth left turners in a signal phase.

Publication of this paper sponsored by Committee on Highway Capacity and Quality of Service. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved

01411368

pp 13-18

1974

Transportation Research Record

53rd Annual Meeting of the Highway Research Board

0309022754

Digital/other

Appendices (1) ; Figures (5) ; References (9) ; Tables (4)

Data collection; Highway capacity; Left turns; Regression analysis; Signalized intersections; Time lapse photography

Data and Information Technology; Highways; Operations and Traffic Management

TRIS, TRB

Oct 5 1974 12:00AM

• AUTOMOBILE-UTILITY TRAILER COMBINATIONS ON RURAL HIGHWAYS IN KENTUCKY
• CONFIGURATION, DESIGN, AND ANALYSIS OF WEAVING SECTIONS