ESTIMATING DEPARTURE TIMES FROM TRAFFIC COUNTS USING DYNAMIC ASSIGNMENT

A dynamic traffic assignment algorithm and observed traffic counts are used to estimate the distribution of departure times in a trip matrix. The objective is to find the maximum entropy distribution of departure times by origin zone subject to observed traffic counts on a subject of network links. The procedure results in the esti mated number of trip departures from each origin in 10-15 minute time intervals of the full analysis period. Such an analysis period will typically range from one to three hours long. We first review the dynamic assignment algorithm developed and tested in a previous paper, and then describe its use with traffic counts to estimate the departure times of a trip matrix. We present an application to a Pittsburgh network in which trip departures are estimated for each 10-minute interval of a peak-hour survey trip matrix. Computat ional advances such as parallel computing will enable the procedure to be run on large networks while counts are being monitored. Such an application may provide near real-time detection of temporal trip departure profiles by origin zone.

• Supplemental Notes:
  • Portions of this document are illegible in microfiche products.
• Corporate Authors:

  Oak Ridge National Laboratory

  P. O. Box 2008
  Oak Ridge, TN  United States  37831
• Authors:
  • Janson, B N
  • Southworth, F
• Publication Date: 1989-7

Media Info

• Features: Figures; References; Tables;
• Pagination: 20 p.

Subject/Index Terms

• TRT Terms: Algorithms; Departure time; Dynamic tests; Equilibrium methods (Structural analysis); Static tests; Traffic counting; Traffic counts; Traffic flow; Travel
• Uncontrolled Terms: Dynamic analysis; Trip
• Old TRIS Terms: Equilibrium methods, structural; Trip tracing
• Subject Areas: Highways; Operations and Traffic Management; I71: Traffic Theory;

Filing Info

• Accession Number: 00494852
• Record Type: Publication
• Source Agency: National Technical Information Service
• Report/Paper Numbers: CONF-900121-1
• Files: TRIS
• Created Date: Jun 30 1990 12:00AM