FREEWAY DATA COLLECTION FOR STUDYING VEHICLE INTERACTIONS - APPENDICES H AND I. FINAL REPORT

The purpose of this study was to develop a series of data sets on microscopic vehicular traffic flow for selected types of freeway bottlenecks sections. The methodology used to develop these data sets involved digitizing vehicle positions from time-lapse aerial photography for a series of freeway sites under 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 mounted in a fix-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 feet -- (760 and 1,370 m). Data were reduced for one hour of the film at each site, with sites ranging between 1,200 and 3,200 feet (370 and 980 m) in length. The data reduction method involved a microcomputer-based digitizing system, producing complete vehicle trajectories for all vehicles passing through the sections studied. The data sets are expected to be useful for both 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. Appendices H and I describe the setup for the digitizing system and present the source code for the computer program. The Technical Report describes the study methodology and data set documentation.

• Supplemental Notes:
  • For the Technical Report see FHWA/RD-85/108 (TRIS 461872).
• Corporate Authors:

  JHK & Associates

  ,    

  Federal Highway Administration

  Office of Research, 1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • SMITH, S A
• Publication Date: 1985-5

Media Info

• Pagination: 33 p.

Subject/Index Terms

• TRT Terms: Aerial photography; Bottlenecks; Data collection; Databases; Digital computers; Freeways; Highway traffic; Merging traffic; Time lapse photography; Traffic flow
• Old TRIS Terms: Digital systems; Freeway traffic
• Subject Areas: Highways; Operations and Traffic Management; I71: Traffic Theory;

Filing Info

• Accession Number: 00461798
• Record Type: Publication
• Source Agency: Federal Highway Administration
• Report/Paper Numbers: FHWA/RD-86/023, FCP 32P1-012
• Contract Numbers: DOT-FH-61-82-C-00001
• Files: TRIS, USDOT
• Created Date: Jan 31 1987 12:00AM