ON KINEMATIC WAVES, II. A THEORY OF TRAFFIC FLOW ON LONG CROWDED ROADS

A FUNCTIONAL RELATIONSHIP BETWEEN FLOW AND CONCENTRATION FOR TRAFFIC ON CROWDED ARTERIAL ROADS HAS BEEN POSTULATED FOR SOME TIME, AND HAS EXPERIMENTAL BACKING. FROM THIS A THEORY OF THE PROPAGATION OF CHANGES IN TRAFFIC DISTRIBUTION ALONG THESE ROADS MAY BE DEDUCED. THE THEORY IS APPLIED TO THE PROBLEM OF ESTIMATING HOW A HUMP OR REGION OF INCREASED CONCENTRATION WILL MOVE ALONG A CROWDED MAIN ROAD. IT IS SUGGESTED THAT IT WILL MOVE SLIGHTLY SLOWER THAN THE MEAN VEHICLE SPEED, AND THAT VEHICLES PASSING THROUGH IT WILL HAVE TO REDUCE SPEED RATHER SUDDENLY (AT A SHOCK WAVE) ON ENTERING IT, BUT CAN INCREASE SPEED AGAIN ONLY VERY GRADUALLY AS THEY LEAVE IT. THE HUMP GRADUALLY SPREADS OUT ALONG THE ROAD, AND THE TIME SCALE OF THIS PROCESS IS ESTIMATED. THE BEHAVIOR OF SUCH A HUMP ON ENTERING A BOTTLENECK, WHICH IS TOO NARROW TO ADMIT THE INCREASED FLOW, IS STUDIED AND METHODS ARE OBTAINED FOR ESTIMATING THE EXTENT AND DURATION OF THE RESULTING HOLD-UP. THE THEORY IS APPLICABLE PRINCIPALLY TO TRAFFIC BEHAVIOR OVER A LONG STRETCH OF ROAD, BUT THE PAPER CONCLUDES WITH A DISCUSSION OF ITS RELEVANCE TO PROBLEMS OF FLOW NEAR JUNCTIONS, INCLUDING A DISCUSSION OF THE STARTING FLOW AT A CONTROLLED JUNCTION. /AUTHOR/

• Supplemental Notes:
  • Series A, VOL 229, NO 1178, PP 317-345, 19 FIG, 16 REF
• Corporate Authors:

  Royal Society of London Proceedings /UK

  ,    
• Authors:
  • LIGHTHILL, M J
  • WHITHAM, G B
• Publication Date: 0

Subject/Index Terms

• TRT Terms: Bottlenecks; Highway traffic; Highways; Intersections; Kinetics; Speed; Traffic flow; Traffic flow theory
• Old TRIS Terms: Vehicular traffic
• Subject Areas: Highways; Operations and Traffic Management;

Filing Info

• Accession Number: 00227113
• Record Type: Publication
• Files: TRIS
• Created Date: Aug 13 2004 6:47PM