CREATION OF DATA SETS TO STUDY MICROSCOPIC TRAFFIC FLOW IN FREEWAY BOTTLENECK SECTIONS

The methodologies employed in an FHWA research study entitled "Freeway Data Collection for Studying Vehicle Interactions" are described. The purpose of this study was to develop a series of data sets on microscopic vehicular traffic flow for selected types of freeway sections. The methodology used to develop these data sets involved digitizing vehicle positions from time-lapse aerial photographs of a series of freeway sites with various geometric configurations. Six types of freeway geometry were of interest: ramp merges, weaving sections, upgrade sections, reduced-width sections, lane drops, and horizontal curves. The aerial photography involved the use of a full-frame 35-mm motion picture camera operating in time-lapse mode mounted in a fixed-wing, short-takeoff-and-landing (STOL) aircraft. The sites were filmed at one frame per second with the aircraft flying clockwise at a slow speed around each site at altitudes ranging between 2,500 and 4,500 ft. Data were reduced to 1 hour of film (3,600 frames) of each site. Sites ranged between 1,200 and 3,200 ft in length. The data reduction method involved a microcomputer-based digitizing system. The most important components of the system were the mathematical techniques for computing vehicle position and the method of vehicle matching, which yielded complete vehicle trajectories for all vehicles passing through the sections studied. The data sets are expected to be useful both for empirical research on freeway traffic flow and for the validation of freeway simulation models. The data sets are being made available to those conducting research in these areas.

• Record URL:
  http://onlinepubs.trb.org/Onlinepubs/trr/1985/1005/1005-014.pdf
• Summary URL:
  https://scholar.google.com/scholar_lookup?title=CREATION+OF+DATA+SETS+TO+STUDY+MICROSCOPIC+TRAFFIC+FLOW+IN+FREEWAY+BOTTLENECK+SECTIONS&author=S.+SMITH&author=M.+Roskin&publication_year=1985
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• Supplemental Notes:
  • 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. Publication of this paper sponsored by Committee on Traffic Flow Theory and Characteristics.
• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Smith, Steven A
  • Roskin, Mark E
• Publication Date: 1985

Media Info

• Media Type: Print
• Features: Figures; Photos; References;
• Pagination: pp 121-128
• Monograph Title: HIGHWAY CAPACITY, TRAFFIC CHARACTERISTICS, AND FLOW THEORY
• Serial:
  • Transportation Research Record
  • Issue Number: 1005
  • Publisher: Transportation Research Board
  • ISSN: 0361-1981

Subject/Index Terms

• TRT Terms: Aerial photography; Bottlenecks; Data collection; Data reduction; Freeways; Highway traffic; Traffic flow
• Old TRIS Terms: Freeway traffic
• Subject Areas: Highways; Operations and Traffic Management; I71: Traffic Theory;

Filing Info

• Accession Number: 00451833
• Record Type: Publication
• ISBN: 0309038154
• Report/Paper Numbers: HS-039 138
• Files: HSL, TRIS, TRB
• Created Date: Dec 31 1988 12:00AM