00495449

Component

http://onlinepubs.trb.org...trr/1989/1239/1239-003.pdf

https://scholar.google.co...lone&publication_year=1989

As part of research conducted to develop a more definitive guide for the selection of divided and undivided sections on urban four-lane roadways in Nebraska, accident experience at signalized and unsignalized intersections on urban four-lane roadways was analyzed to assess the safety effects of left-turn lanes. Results of this analysis are presented. Multivehicle accidents on intersection approaches with left-turn lanes were compared with those on similar approaches without left-turn lanes. The degree to which left-turn lanes on signalized and on uncontrolled approaches reduced accidents was computed. The statistical significance of the percent reductions was determined using the chi-squared test. Left-turn lanes at intersections on urban four-lane roadways were found to significantly reduce rear-end, sideswipe, and left-turn accidents. However, on the uncontrolled approaches of intersections on urban undivided roadways, left-turn lanes were found to significantly increase right-angle accidents, as well as reduce rear-end, sideswipe, and left-turn accidents.

This paper appears in Transportation Research Record No. 1239, Geometric Design and Operational Effects. 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

01414248

p. 17-22

1989

Transportation Research Record

0309049660

References (11) ; Tables (7)

Crashes; Four lane highways; Left turn lanes; Rear end crashes; Safety; Side crashes; Signalized intersections; Unsignalized intersections

Design; Highways; Operations and Traffic Management; Safety and Human Factors; I20: Design and Planning of Transport Infrastructure; I73: Traffic Control; I80: Accident Studies

TRIS, TRB, ATRI

Jul 31 1990 12:00AM

• ACCIDENT COMPARISON OF RAISED MEDIAN AND TWO-WAY LEFT-TURN LANE MEDIAN TREATMENTS
• DEVELOPMENT OF HIGHWAY ALIGNMENT INFORMATION FROM PHOTOLOG DATA
• EVALUATION OF NEW PASSING ZONE GORE DESIGN
• HIGHWAY VERTICAL ALIGNMENT ANALYSIS BY DYNAMIC PROGRAMMING
• INTERACTIVE INTERSECTION DESIGN USING AN EXPERT SYSTEMS APPROACH
• INTERSECTION, DIAMOND, AND THREE-LEVEL DIAMOND GRADE SEPARATION BENEFIT-COST ANALYSIS BASED ON DELAY SAVINGS