COMPARISON OF LEFT-TURN ACCIDENT RATES FOR DIFFERENT TYPES OF LEFT-TURN PHASING

Left-turn accident rates are compared for five types of left-turn phasing: permissive; leading exclusive/permissive; lagging exclusive/permissive; leading exclusive; and lagging exclusive. Two different study designs were used to compare left-turn accident rates; both a simple comparison design and a simple before-and-after design were used. Left-turn accident rate (number of left-turn accidents per million left-turning vehicles) is used to compare the relative safety of the different types of left-turn phasing. Left-turn accident rates are shown for each type of left-turn phasing and are further subdivided by whether there are two or three lanes of opposing traffic, by left-turn volume, and by opposing volume. The before-and-after data are categorized according to the types of left-turn phasing in the before and after periods. Observations and conclusions are made about the effect of volume, number of lanes of opposing traffic, and type of left-turn phasing on the accident rate.

• Record URL:
  • http://onlinepubs.trb.org/Onlinepubs/trr/1991/1324/1324-005.pdf
• Record URL:
  • https://scholar.google.com/scholar_lookup?title=COMPARISON+OF+LEFT-TURN+ACCIDENT+RATES+FOR+DIFFERENT+TYPES+OF+LEFT-TURN+PHASING&author=J.+Upchurch&publication_year=1991
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• Supplemental Notes:
  • This paper appears in Transportation Research Record No. 1324, Communications, Traffic Signals, and Traffic Control Devices 1991. 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
• Authors:
  • Upchurch, Jonathan
• Publication Date: 1991

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 33-40
• Monograph Title: Communications, traffic signals, and traffic control devices, 1991
• Serial:
  • Transportation Research Record
  • Issue Number: 1324
  • Publisher: Transportation Research Board
  • ISSN: 0361-1981

Subject/Index Terms

• TRT Terms: Before and after studies; Crash rates; Exclusive permissive phasing; Exclusive phasing; Left turn phase; Opposing traffic; Permissive phasing; Traffic lanes; Traffic safety; Traffic volume
• Old TRIS Terms: Left turn phasing
• Subject Areas: Highways; Operations and Traffic Management; I73: Traffic Control;

Filing Info

• Accession Number: 00622202
• Record Type: Publication
• ISBN: 0309051703
• Files: TRIS, TRB, ATRI
• Created Date: May 31 1992 12:00AM