Safety Impacts of a Modified Right Turn Lane Design at Intersections

From 2006 to 2014, ten right turn approaches in the Peoria, Illinois area were selected and reconstructed with a modified right turn lane design. The major purpose of the modified design was to improve the line of sight for passenger vehicles attempting to turn right, while also accommodating semi-tractor trailer trucks. While the actual changes varied among intersections, the final result at each was an improvement to the approach angle for right turning vehicles stopped to view cross traffic. The authors of this paper are involved in funded research to study the impacts of the modifications, utilizing a driver behavior analysis and a crash-based safety evaluation. The driver behavior field investigations, which included both a comparative test and control analysis at ten sites, and a before and after analysis at three sites, indicated that line of site and approach angle was improved due to less drivers requiring exaggerated head turns to complete the right turn, less roll and go stops, and more vehicles stopping at the stop bar when a stop was required. Additionally, the crash-based safety analysis, using the Empirical Bayes method revealed statistically significant reductions in total intersection crashes and right turn related crashes at the subject approaches after the modifications were made. Based upon these results, it is recommended that improving the right turn approach angle by reducing the skew of the right turn approach be considered as a safety measure for sites experiencing right turn related crashes.

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• Supplemental Notes:
  • This paper was sponsored by TRB committee AFB10 Standing Committee on Geometric Design.
• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Schattler, Kerrie L
  • Hanson, Trevor
• Conference:
  • Transportation Research Board 95th Annual Meeting
  • Location: Washington DC, United States
  • Date: 2016-1-10 to 2016-1-14
• Date: 2016

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; References; Tables;
• Pagination: 15p
• Monograph Title: TRB 95th Annual Meeting Compendium of Papers

Subject/Index Terms

• TRT Terms: Bayes' theorem; Behavior; Drivers; Field studies; Highway design; Highway safety; Line of sight; Right turn lanes; Signalized intersections; Traffic crashes
• Geographic Terms: Peoria (Illinois)
• Subject Areas: Design; Highways; Safety and Human Factors; I20: Design and Planning of Transport Infrastructure; I80: Accident Studies;

Filing Info

• Accession Number: 01590862
• Record Type: Publication
• Report/Paper Numbers: 16-0790
• Files: PRP, TRIS, TRB, ATRI
• Created Date: Feb 24 2016 8:32AM