CAR FOLLOWING AND ACCELERATION NOISE

THE AVERAGE SPEED OR TRAVEL TIME FOR A SMOOTH SAFE DRIVING ON A GIVEN ROAD DEPENDS ON MANY PHENONMENA. TWO FACTORS DETERMINE THE MAINTENANCE OF A SMOOTH SAFE TRIP: THE MOTION OF AN ISOLATED VEHICLE, AND THE INTERFERENCE OF VEHICLES WITH EACH OTHER. THE ACCELERATION PATTERN OF AN ISOLATED VEHICLE, AS A FUNCTION OF TIME, HAS A RANDOM APPEARANCE CALLED ACCELERATION NOISE. A MATHEMATICAL EQUATION IS DESIRED TO EXPRESS ACCELERATION NOISE OF DISPERSION. METHODS OF MEASURING ACCELERATION NOISE ARE DESCRIBED. EQUATIONS ARE DERIVED TO EXPRESS THE LAW OF CAR FOLLOWING IN VARIATION OF FLOW WITH DENSITY. THE EFFECT OF DISTURBANCES AND OF STABILITY OF LINEAR SYSTEMS IS FREQUENTLY INVESTIGATED BY MAKING HARMONIC (FREQUENCY) ANALYSIS OF THE DISTURBANCE TO SEE HOW INDIVIDUAL FREQUENCY COMPONENTS ARE PROPAGATED THROUGH THE SYSTEM. THE HARMONIC ANALYSIS IS MADE AND COMPARED WITH EXPERIMENTAL DATA. HAVING ANALYZED ACCELERATION NOISE OF AN ISOLATED VEHICLE AND SEVERAL SIMPLE CAR-FOLLOWING LAWS FOR TRAFFIC, IT IS ASSUMED THAT THE TOTAL ACCELERATION NOISE OF A VEHICLE IN TRAFFIC IS A SUPERPOSITION OF ITS NATURAL NOISE AND ITS RESPONSE TO THAT OF ITS PREDECESSORS THROUGH THE LAW OF FOLLOWING. ANALYSIS BY HERMAN AND ROTHERY INDICATE THAT TRAFFIC BROADENS THE ACCELERATION DISTRIBUTION FUNCTION SO THAT THE DISPERSION FAR DOWN THE PLATOON IS ABOUT THREE TIMES THAT OF THE LEAD CAR, WHICH IS EFFECTIVELY MOVING FREELY ON THE ROAD. THE BROADENING OF THE ACCELERATION DISTRIBUTION BY TRAFFIC DEPENDS ON THE PARAMETERS OF THE LAW OF FOLLOWING. AN EQUATION IS DERIVED TO EXPRESS THESE VALUES.

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• Supplemental Notes:
  • pp 37-48, 5 FIG, 2 TAB, 8 REF
• Corporate Authors:

  Highway Research Board

  2101 Constitution Avenue, NW
  Washington, DC    20418
• Authors:
  • Montroll, E W
  • Potts, R B
• Publication Date: 1964

Media Info

• Media Type: Print
• Features: Figures; References; Tables;
• Pagination: pp 37-48
• Monograph Title: AN INTRODUCTION TO TRAFFIC FLOW THEORY
• Serial:
  • Highway Research Board Special Report
  • Issue Number: 79
  • Publisher: Highway Research Board

Subject/Index Terms

• TRT Terms: Acceleration (Mechanics); Car following; Mathematical analysis; Traffic density; Traffic flow; Traffic platooning; Traffic speed; Travel time
• Old TRIS Terms: Overall travel speed
• Subject Areas: Highways; Safety and Human Factors;

Filing Info

• Accession Number: 00223209
• Record Type: Publication
• Files: TRIS, TRB
• Created Date: Aug 17 1970 12:00AM