Benefit analysis is particularly in need for one popular ITS technique: ramp metering systems. The reported benefits of ramp metering systems range widely and little analysis has been performed to determine the magnitude and cause of this discrepancy. There is such a wide range of opinions that some transportation professionals are currently questioning whether ramp meters generate any benefits at all. The variation in opinions is largely due to the fact that the relationship between the performance and cost of ramp metering systems is not well understood. Without understanding what factors cause ramp meters to perform well, it is very difficult to efficiently design a new ramp metering system. Additionally, insufficient analysis of prior benefits causes difficulty for transportation engineers attempting to make rational design decisions based on past results. This study investigates the benefit-cost relationship of ramp metering systems by constructing a performance-cost tradeoff curve that displays the maximum achievable performance for any budget. A simulation- optimization methodology was developed to generate the tradeoff curve. This methodology employs heuristic search techniques to locate the optimal ramp metering deployment scheme (quantity and location of equipment) for each budget. All deployment schemes are evaluated using CORSIM, a traffic simulation tool. The performance-cost curve constructed by the simulation-optimization methodology has the shape of a step function. Significant benefits are possible with only a small initial investment, however, beyond this initial step diminishing returns are experienced as benefits slowly increase with additional spending. Analysis of the tradeoff curve provides valuable information about the performance-cost relationship and ramp metering systems in general. Recommendations for improving ramp metering implementation are developed using this information

  • Record URL:
  • Supplemental Notes:
    • Publication Date: September 2000. National ITS Implementation Research Center, George Mason University, Fairfax VA. Format: website
  • Corporate Authors:

    National ITS Implementation Research Center

  • Authors:
    • Clark, David C
    • Scherer, William T
    • Smith, Brian Lee
  • Publication Date: 2000


  • English

Subject/Index Terms

Filing Info

  • Accession Number: 00962435
  • Record Type: Publication
  • Source Agency: UC Berkeley Transportation Library
  • Report/Paper Numbers: UVA-CE-ITS-01-2
  • Files: PATH, NTL
  • Created Date: Sep 2 2003 12:00AM