DETECTING FREEWAY INCIDENTS UNDER LOW-VOLUME CONDITIONS

Two computer algorithms for automatic, freeway-incident detection under low-volume conditions were developed. The first approach uses a time-scan process. The second approach, considered to be superior to the first, operates on an event-scan principle. Computer simulations produced a family of curves that are useful in determining sensor- spacing requirements for an operational system using the event-scan algorithm. The results indicate that, when detector spacings of 1,000 ft (304.8 m) are used, all incidents on a 3-lane freeway section can be detected within 3 min for volumes up to 500 vehicles per hour. When volumes approach 1,000 vehicles per hour, 85 percent of the incidents can be detected within 3 min. Faster detection capabilities at the higher volumes would require closer detector spacings. Incident-detection operational considerations, particularly the manner in which software can be developed to recognize and compensate for vehicle-count errors produced by semitrailers and lane-change maneuvers, also are discussed.

• Record URL:
  • http://onlinepubs.trb.org/Onlinepubs/trr/1975/533/533-003.pdf
• Summary URL:
  • https://scholar.google.com/scholar_lookup?title=DETECTING+FREEWAY+INCIDENTS+UNDER+LOW-VOLUME+CONDITIONS&author=C.+Dudek&author=G.+Weaver&author=G.+Ritch&author=C.+Messer&publication_year=1975
• Availability:
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• Supplemental Notes:
  • Publication of this paper sponsored by Committee on Freeway 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:
  • Dudek, Conrad L
  • Weaver, Graeme D
  • Ritch, Gene P
  • Messer, Carroll J
• Discussers:
  • Wattleworth, Joseph A
  • McDermott, Joseph M
  • PAYNE, HAROLD J
• Conference:
  • 54th Annual Meeting of the Transportation Research Board
  • Location: Washington District of Columbia
  • Date: 1975-1-13 to 1975-1-17
• Publication Date: 1975

Media Info

• Media Type: Print
• Features: Figures; References; Tables;
• Pagination: pp 34-47
• Monograph Title: Freeway Entry, Flow, and Control
• Serial:
  • Transportation Research Record
  • Issue Number: 533
  • Publisher: Transportation Research Board
  • ISSN: 0361-1981

Subject/Index Terms

• TRT Terms: Algorithms; Detection and identification; Detectors; Freeways; Operations; Simulation; Spacing; Traffic incidents; Traffic volume; Vehicle detectors
• Uncontrolled Terms: Incidents
• Old TRIS Terms: Operational effects
• Subject Areas: Administration and Management; Highways; Operations and Traffic Management;

Filing Info

• Accession Number: 00099661
• Record Type: Publication
• ISBN: 030902384X
• Files: TRIS, TRB
• Created Date: Nov 5 1975 12:00AM