Addressing Bicycle-Vehicle Conflicts with Alternate Signal Control Strategies

Over the last decade there has been increased interest in promoting active and sustainable transportation modes such as bicycling and walking especially in urban areas, as a means to alleviate congestion, lower emission levels and improve personal health. In urban areas, intersections are locations where a variety of modes converge, thus increasing the propensity for conflicts. Many bicycle-vehicle crashes occur at intersections. A common crash type involving bicycles at intersections is the “right-hook” where a right-turning vehicle collides with a through bicyclist. Intersections are also the source of increased stress for many bicyclists where the interactions with cars are more pronounced. Geometric treatments such as pavement markings, bike boxes, colored lanes, and shared right-turn lane designs have been implemented in an attempt to alleviate the problem. While the use of signal timing treatments has been limited until now, cities are beginning to explore treatments such as leading bicycle intervals, split leading bicycle intervals and exclusive phasing using bicycle specific signals. While exclusive phasing eliminates the bicycle-vehicle conflict by separating the phases and restricting turns, the trade-off is a decrease in efficiency at the intersection with increased delays for all users. An emerging operational treatment at intersections is to provide a split leading bicycle interval (split LBI), with concurrent green for bicycles, pedestrian walk and green for the through vehicles while restricting or essentially delaying the right turn for vehicles. After a certain time, the restriction on turns is lifted. The same treatment could also be used for pedestrians and offers advantages over the traditional leading bike and pedestrian intervals (LBI, LPI) in that there is no lost time for through vehicles. This study will evaluate various signal timing control strategies that are designed to minimize conflicts between bicycles, pedestrians and turning vehicles using micro simulation, deployment and video based conflict analysis to study efficiency and safety impacts.

Language

  • English

Project

  • Status: Active
  • Funding: $303342
  • Contract Numbers:

    NITC 897

  • Sponsor Organizations:

    Office of the Assistant Secretary for Research and Technology

    University Transportation Centers Program
    Department of Transportation
    Washington, DC  United States  20590

    City of Flagstaff

    211 West Aspen Ave
    Flagstaff, Arizona  United States  86001

    City of Portland

    1120 SW Fifth Avenue, Suite 800
    Portland, Oregon  United States  97204

    Portland State University

    Department of Civil and Environmental Engineering
    Engineering Bldg, 301D, 1930 SW 4th Ave.
    Portland, OR  United States  97201

    Northern Arizona University

    Civil and Environmental Engineering
    PO box 15600
    Flagstaff, Arizona  United States  86011
  • Managing Organizations:

    TREC at Portland State University

    1900 SW Fourth Ave, Suite 175
    P.O. Box 751
    Portland, Oregon  United States  97201
  • Project Managers:

    Hagedorn, Hau

  • Performing Organizations:

    Portland State University

    Department of Civil and Environmental Engineering
    Engineering Bldg, 301D, 1930 SW 4th Ave.
    Portland, OR  United States  97201

    Northern Arizona University

    Civil and Environmental Engineering
    PO box 15600
    Flagstaff, Arizona  United States  86011
  • Principal Investigators:

    Kothuri, Sirisha

    Monsere, Chris

    Nordback, Krista

    Smaglik, Edward

  • Start Date: 20150801
  • Expected Completion Date: 20171231
  • Actual Completion Date: 0

Subject/Index Terms

Filing Info

  • Accession Number: 01632278
  • Record Type: Research project
  • Source Agency: National Institute for Transportation and Communities
  • Contract Numbers: NITC 897
  • Files: UTC, RiP
  • Created Date: Apr 13 2017 12:24PM