REAL-TIME METERING ALGORITHM FOR CENTRALIZED CONTROL

In response to growing freeway congestion problems in the Seattle area, the Washington State Department of Transportation (WSDOT) initiated a ramp-control program in 1981 as part of a region-wide transportation system management effort. The ramp-metering system is a computer-based, distributed intelligence system that consists of field-located microprocessors and a centralized computer system. It is an integrated, traffic-responsive metering system. The system uses an algorithm that calculates metering rates in real time based on systemwide traffic conditions. The algorithm is simple in its approach but very effective in its application. The system has proven to be effective in a series of ongoing evaluations. In this paper, the WSDOT real-time ramp-metering algorithm is described. First a brief description of the Seattle area freeway system and an overview of the development of the ramp metering system are provided. The components of the surveillance, control, and driver information system are then described, followed by a description of the physical elements of the ramp-metering system. After the real-time algorithm used, the limitations of the algorithm, and the advantages of the algorithm are described, the results of an ongoing evaluation effort are presented. Finally, further actions being planned are described.

• Record URL:
  http://onlinepubs.trb.org/Onlinepubs/trr/1989/1232/1232-003.pdf
• Record URL:
  https://scholar.google.com/scholar_lookup?title=REAL-TIME+METERING+ALGORITHM+FOR+CENTRALIZED+CONTROL&author=L.+Jacobson&author=K.+Henry&author=O.+Mehyar&publication_year=1989
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• Supplemental Notes:
  • This paper appears in Transportation Research Record No. 1232, Urban Traffic Systems and Operations. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved
• Authors:
  • Jacobson, Leslie N
  • Henry, Kim C
  • Mehyar, Omar
• Publication Date: 1989

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 17-26
• Monograph Title: Urban traffic systems and operations
• Serial:
  • Transportation Research Record
  • Issue Number: 1232
  • Publisher: Transportation Research Board
  • ISSN: 0361-1981

Subject/Index Terms

• TRT Terms: Algorithms; Centralized traffic control; Components; Measures of effectiveness; Microprocessors; Performance evaluations; Ramp metering; Real time control; Real time data processing
• Uncontrolled Terms: Effectiveness
• Old TRIS Terms: Centralized control
• Subject Areas: Highways; Operations and Traffic Management; I73: Traffic Control;

Filing Info

• Accession Number: 00494978
• Record Type: Publication
• ISBN: 0309049601
• Files: TRIS, TRB, ATRI
• Created Date: Jun 30 1990 12:00AM