Measuring the Equity and Efficiency of Ramp Meters

Traffic congestion has become an increasingly serious problem in many cities. Ramp metering, which maintains smooth freeway mainline flow by limiting vehicle entry at entrance ramps, has been proposed and implemented in a number of metropolitan areas in and outside the U.S. to mitigate freeway congestion. This study aims to develop both efficient and equitable freeway ramp control strategies. Traffic conditions with and without ramp metering are evaluated on several representative freeways in the Twin Cities with a comprehensive set of performance measures. A unified theory for ramp metering is proposed based on a linear programming model of freeway traffic dynamics. The most efficient ramp control algorithm is found to be also the least equitable one. A novel control objective, minimizing weighted or perceived travel time, is therefore proposed to balance efficiency and equity objectives of ramp metering. This research also develops a new family of applicable ramp metering strategies, which consider both efficiency and equity, and are demonstrated in a microscopic traffic simulator. Future studies should compare various traffic control methods under the analytical framework proposed in this report. Researchers should also pursue field experiments of the proposed multi-objective ramp control strategies.

  • Record URL:
  • Corporate Authors:

    University of Minnesota, Twin Cities

    Department of Civil Engineering, 500 Pillsbury Drive, SE
    Minneapolis, MN  United States  55455

    Minnesota Department of Transportation

    Office of Research Services, 395 John Ireland Boulevard
    St Paul, MN  United States  55155
  • Authors:
    • Levinson, David
    • Zhang, Lei
    • Das, Shantanu
    • Sheikh, Atif
  • Publication Date: 2004-11


  • English

Media Info

  • Media Type: Web
  • Edition: Final Report
  • Features: Figures; References; Tables;
  • Pagination: 102p

Subject/Index Terms

Filing Info

  • Accession Number: 01013364
  • Record Type: Publication
  • Report/Paper Numbers: MN/RC-2004-37
  • Contract Numbers: (c)74708 (wo)162
  • Created Date: Dec 11 2005 5:30PM