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