FREEWAY RAMP CONTROL USING FUZZY SET THEORY FOR INEXACT REASONING

This paper presents a fuzzy controller for freeway ramp metering, which uses rules of the form: IF "freeway condition" THEN "control action." The controller has been designed to consider varied levels of congestion, a downstream control area, changing occupancy levels, upstream flows, and a distributed detector array in its rule base. Through fuzzy implications, the inference of each rule is used to the degree to which the condition is true. Using a dynamic simulation model of conditions at the San Francisco-Oakland Bay Bridge, the action of the fuzzy controller is compared to the existing "crisp" control scheme, and an idealized controller. Tests under a variety of scenarios with different incident locations and capacity reductions show that the fuzzy controller is able to extract 40 to 100 per cent of the possible savings in passenger-hours. In general, the fuzzy algorithm displays smooth and rapid response to incidents, and significantly reduces the minute-miles of congestion.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/09658564
• Corporate Authors:

  Pergamon Press, Incorporated

  Headington Hill Hall
  Oxford OX30BW,    
• Authors:
  • Chen, L L
  • May, A D
  • Auslander, D M
• Publication Date: 1990-1

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 15-25
• Serial:
  • Transportation Research Part A: Policy and Practice
  • Volume: 24A
  • Issue Number: 1
  • Publisher: Elsevier
  • ISSN: 0965-8564
  • Serial URL: http://www.sciencedirect.com/science/journal/09658564

Subject/Index Terms

• TRT Terms: Algorithms; Expert systems; Fuzzy sets; Ramp metering; Ramps (Interchanges); Simulation; Traffic congestion
• Old TRIS Terms: Freeway ramps
• Subject Areas: Highways; Operations and Traffic Management; Planning and Forecasting;

Filing Info

• Accession Number: 00492281
• Record Type: Publication
• Files: TRIS, ATRI
• Created Date: Mar 31 1990 12:00AM