Design and Evaluate Coordinated Ramp Metering Strategies for Utah Freeways

During the past decades, ramp metering (RM) control has been widely implemented in many states of the U.S., including Utah. In practice, it can reduce overall freeway congestion by managing the amount of traffic entering the freeway and by breaking up platoons that make it difficult to merge onto the freeway. RM controllers can be implemented as coordinated or uncoordinated systems. When operating an uncoordinated RM, the metering rate and on/off statuses will be determined by local traffic conditions. Uncoordinated RM strategies include fixed, local, and corridor-responsive systems. Despite the improvements to the operational efficiency of mainline flows, RM will inevitably create additional delays to the ramp flows. As traffic demand for a freeway facility increases, mitigating mainline congestion could go beyond the capability of uncoordinated RMs. Recognizing such limitations, the proposed research aims to assist the on-going and future efforts to deploy coordinated RM systems and evaluate the performance of deployed systems. The research can benefit the transportation community by helping (1) understand potential ramp delays to achieve a target mainline congestion level; (2) identify the locations that would benefit from coordinated RMs; and (3) evaluate the system performance from both operational and safety aspects.


  • English


  • Status: Completed
  • Funding: $170000
  • Contract Numbers:


  • Sponsor Organizations:

    Office of the Assistant Secretary for Research and Technology

    University Transportation Centers Program
    Department of Transportation
    Washington, DC  United States  20590
  • Managing Organizations:

    Mountain-Plains Consortium

    North Dakota State University
    Fargo, ND  United States  58108
  • Project Managers:

    Tolliver, Denver

  • Performing Organizations:

    Dept. of Civil and Environmental Engineering

    University of Utah
    Salt Lake City, UT  United States 
  • Principal Investigators:

    Yang, Xianfeng

  • Start Date: 20201030
  • Expected Completion Date: 20230731
  • Actual Completion Date: 20221121
  • USDOT Program: University Transportation Centers Program
  • Source Data: MPC-641

Subject/Index Terms

Filing Info

  • Accession Number: 01757774
  • Record Type: Research project
  • Source Agency: Mountain-Plains Consortium
  • Contract Numbers: 69A3551747108
  • Files: UTC, RIP
  • Created Date: Nov 16 2020 6:43AM