Addressing Bicycle-Vehicle Conflicts with Alternate Signal Control Strategies
There is nationwide interest in supporting sustainable and active transportation modes such as bicycling and walking due to the many benefits associated with them, including reduced congestion, lower emissions and improved health. Although the number of bicyclists is increasing, safety remains a top concern. In urban areas, a common crash type involving bicycles at intersections is the “right hook” where a right-turning vehicle collides with a through bicyclist. While geometric treatments and pavement markings have been studied, there is a lack of research on signal timing treatments to address right-hook bicycle-vehicle conflicts. This study analyzed the operational impacts of traditional concurrent phasing, leading bike intervals (LBI), split leading bike intervals, and exclusive bike phasing in a microsimulation environment, and explored the safety impacts of traditional concurrent phasing, leading bike intervals, split leading bike intervals, and mixing zones using video-based conflict analysis. The microsimulation analysis revealed increased delays due to LBI, split LBI and exclusive bike phasing for the affected motor vehicle phases compared to traditional concurrent phasing. Using post-encroachment time (PET), a surrogate safety measure, conflicts between turning vehicles and bicyclists were investigated. While the split LBI treatment was useful in mitigating conflicts during the lead interval, the risk for bicyclists is shifted to the stale green portion of the phase. No correlations were found between the frequency of conflicts and elapsed time since green. With the mixing zone treatment, significant confusion was exhibited by both cyclists and drivers, with respect to the correct action to be taken. These observations also revealed that a significant percentage of the vehicles merged into the mixing zone at the very last second, thus adding to the confusion. This study provides broad-based recommendations on the appropriate treatment to be implemented to reduce right-hook conflicts.
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- Summary URL:
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Supplemental Notes:
- This document was sponsored by the U.S. Department of Transportation, University Transportation Centers Program.
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Corporate Authors:
Portland State University
Portland, OR United States 97207Northern Arizona University
Flagstaff, AZ United States 86011National Institute for Transportation and Communities
Portland State University
P.O. Box 751
Portland, OR United States 97207Transportation Research and Education Center
1900 S.W. Fourth Ave., Suite 175
Portland, OR United States 97201Office of the Assistant Secretary for Research and Technology
University Transportation Centers Program
Department of Transportation
Washington, DC United States 20590 -
Authors:
- Kothuri, Sirisha
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0000-0002-2952-169X
- Smaglik, Edward
- Kading, Andrew
- Schrope, Andrew
- Aguilar, Christopher
- Gil, William
- White, Kelly
- Publication Date: 2018-4
Language
- English
Media Info
- Media Type: Digital/other
- Features: Figures; Photos; References; Tables;
- Pagination: 107p
Subject/Index Terms
- TRT Terms: Bicycle crashes; Microsimulation; Right turn on red; Traffic safety; Traffic signal control systems; Traffic signal timing
- Candidate Terms: Bicycle vehicle interface
- Subject Areas: Highways; Operations and Traffic Management; Pedestrians and Bicyclists; Safety and Human Factors;
Filing Info
- Accession Number: 01670968
- Record Type: Publication
- Report/Paper Numbers: NITC-RR-897
- Files: UTC, NTL, TRIS, ATRI, USDOT
- Created Date: May 29 2018 4:05PM