Evaluating the Performance of Right-Turn-On-Red Operation at Signalized Intersections (with single and dual right-turn lanes)

Right-turn on red (RTOR) has been used since the 1970s as an efficient strategy to reduce delay and fuel consumption at signalized intersections. Most studies on this subject focused only on safety concerns, dedicating little attention to its operational benefits. In the absence of a country-wide accepted methodology, alternative tools are often the only resource to estimate traffic behavior on arterials where RTOR is permitted. Empirical models, however, are still necessary in order to verify if the results produced by alternative tools are compatible with field conditions. This strategy is widely accepted as an effective approach to reduce control delay at intersections, especially for high demands on right-turn movements. However, the conflicting movement of pedestrian crossing is a critical issue to be addressed, from both operational and safety standpoints. Although a reference methodology to evaluate and plan RTOR operations is desired, it is unlikely that it will be widely implemented if it will bring significant negative impacts on pedestrians and vehicle safety. Additionally, high density pedestrian flows may undermine the benefits of RTOR implementation. This trade-off between operations and safety can be found in empirical studies throughout the literature, but a reference methodology to evaluate this issue is still not present. The Highway Capacity Manual (HCM), in its 6th edition, lacks a methodology to estimate the RTOR flow volume and its effect on delays, leaving field counts as the only option for obtaining this input, which is then subtracted from total right-turn movements. This may be feasible for operational analyses on existing intersections, but it is not reliable for either planning- or operational-level applications. Some of the main gaps in the HCM methodology and aspects that need to be addressed are: (1) The lack of a volume prediction model for resulting right-turn delay. In the current method, input values must be obtained through field observations and subtracted from the right-turn volumes. The suggested default value for right-turn volume on red is 0 veh/h, due to the difficulty to estimate it without the support of field data. This is a conservative estimate, and may lead to inaccurate performance estimations. (2) The RTOR flow rate should also be used as input for pedestrian methodology and may be affected by pedestrian volumes. (3) No guidelines are provided on whether RTOR should be implemented or not. Agencies throughout the country have performed their own research on this topic, probably due to the lack of a reference methodology to evaluate RTOR operations. The development of an HCM methodology is expected to assist agencies and practitioners, especially those who do not have a consolidated body of knowledge on RTOR analysis. The objective of this research project is to develop methods to evaluate right-turn on red (RTOR) operation that can be implemented in the Highway Capacity Manual methodology for signalized intersections and urban arterials.  


  • English


  • Status: Proposed
  • Funding: $300000
  • Contract Numbers:

    Project 03-136

  • Sponsor Organizations:

    National Cooperative Highway Research Program

    Transportation Research Board
    500 Fifth Street, NW
    Washington, DC  United States  20001

    American Association of State Highway and Transportation Officials (AASHTO)

    444 North Capitol Street, NW
    Washington, DC  United States  20001

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Project Managers:

    Crichton-Sumners, Camille

  • Start Date: 20180619
  • Expected Completion Date: 0
  • Actual Completion Date: 0

Subject/Index Terms

Filing Info

  • Accession Number: 01669536
  • Record Type: Research project
  • Source Agency: Transportation Research Board
  • Contract Numbers: Project 03-136
  • Files: TRB, RiP, USDOT
  • Created Date: May 21 2018 3:07PM