INVESTIGATION OF THE DYNAMICS OF PLATOON DISPERSION

AN INVJESTIGATION IS BEING CONDUCTED TO RELATE DISPERSION CHARACTERISTICS OF PLATOONS ON SIGNALIZED ARTERIALS TO SIGNAL SPACING AND PLATOON SIZE. A 16-MM TIME-LAPSE CAMERA WAS USED TO COLLECT DATA ON PLATOON DISPERSION CHARACTERISTICS. BY SWITCHING ONE TRAFFIC SIGNAL TO FLASHING AMBER, THE SPACING BETWEEN THE PLATOON FORMATION POINT AND THE FIRST REGULAR TRAFFIC SIGNAL WAS INCREASED BY 597 FT. THE CHANGE CAUSED THE PLATONS TO SPREAD MORE ALTHOUGH THE BEHAVIOR OF THE LEAD VEHICLE DID NOT CHANGE. THE DIFFERENCE WAS STATISTICALLY SIGNIFICANT FOR SMALLER SIZED PLATOONS ONLY. VEHICLES WERRE FOUND TO BE MORE CLOSELY PACKED IN LARGER PLATOONS THAN IN SMALLER PLATOONS. THE DIMENSIONLESS DIFFUSION CONSTANT, DEFINED AS THE RATIO OF THE STANDARD DEVIATION OF THE SPEED DISTRIBUTION AND ITS MEAN SPEED, WAS USED TO PREDICT ARRIVAL FREQUENCIES AT ONE POINT DOWNSTREAM FROM THE TRAFFIC SIGNAL. THE DIFFERENCE BETWEEN THE THEORETICAL ARRIVAL FREQUENCY DISTRIBUTION AND THE OBSERVED FREQUENCY DISTRIBUTION WAS NOT STATISTICALLY SIGNIFICANT. THE MEAN HEADWAYS OF OFF-PEAK -HOUR AND PEAK-HOUR PLATOONS FOR IDENTICAL PLATOON SIZES WERE COMPARED. THE DIFFERENCE WAS NOT STATISTICALLY SIGNIFICANT. THE PRELIMINARY RESULTS OF THIS STUDY JUSTIFY FURTHER INVESTIGATION ON A MORE COMPREHENSIVE SCALE. A HELICOPTER-MOUNTED METRIC AERIAL CAMERA IS CURRENTLY BEING USED TO COLLECT DATA ON ONE-WAY SIGNALIZED ARTERIALS. A SEMIAUTOMATIC MONOCOMPARATOR IS BEING USED FOR DATA ANALYSIS. THE DATA ARE BEING INCORPORATED INTO A MATHEMATICAL MODEL FOR DESCRIBING THE BEHAVIOR OF A PLATOON OF VEHICLES AS IT PASSES THROUGH A SERIES OF SIGNALIZED INTERSECTIONS. /AUTHOR/

Media Info

  • Media Type: Print
  • Features: Figures; References;
  • Pagination: pp 23-33
  • Monograph Title: Traffic flow theory
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00227306
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: Jun 11 1971 12:00AM