IMPROVEMENT OF TRAFFIC FLOW AND SAFETY BY LONGITUDINAL CONTROL

A THEORY OF LONGITUDINAL TRAFFIC CONTROL /MONITORING THE SPACING OF A PLATOON OF VEHICLES TRAVELLING IN A SINGLE TRAFFIC LANE/ IS DEVELOPED. TWO CONCEPTS ARE INVESTIGATED' /1/ SAFE TRAFFIC FLOW BY CONSIDERING THE POSSIBILITY THAT A LEADING VEHICLE MAY COME TO A SUDDEN STOP BY RUNNING INTO A STATIONARY /FIXED/ OBJECT, AND /2/ MARGINALLY SAFE FLOW BY CONSIDERING THE POSSIBILITY THAT A LEADING VEHICLE IS FORCED TO BRAKE TO A STOP IN AN EMERGENCY. THE INFLUENCE OF REACTION /PIEV/ TIME AND SPACING IS STUDIED FOR BOTH SAFETY CONCEPTS, AND THE THEORETICALLY POSSIBLE TRAFFIC FLOW IS DETERMINED FOR A VELOCITY RANGE UP TO 60 MPH. VEHICLE TRAJECTORIES OBTAINED BY AERIAL SURVEY METHODS IN FIELD STUDIES WERE EVALUATED TO DETERMINE THE DEGREE OF SAFETY IN PRESENT CAR FOLLOWING SITUATIONS. FIVE DIFFERENT CONCEPTS OF SAFETY FLOW OR MARGINALLY SAFE FLOW WITH REACTION TIME WERE STUDIED. IT IS FOUND THAT AT LEAST 40 PERCENT OF THE DRIVERS DO NOT MEET THE ENTAILED SPACING FOR SAFE DRIVING ACCORDING TO THE DIFFERENT SAFETY CONCEPTS. DIAGRAMS OF THE CUMULATIVE DISTRIBUTION AND THE RELATIONSHIP BETWEEN VELOCITY AND THE MEAN SAFETY FACTOR ARE GIVEN. TWO FEASIBLE LONGITUDINAL CONTROL SYSTEMS ARE DEVELOPED AND THEIR MERITS IN REGARD TO FLOW AND STABILITY OF TRAFFIC MOVEMENT ARE DISCUSSED FOR A MARGINALLY SAFE SYSTEM. IT IS CONCLUDED THAT A LONGITUDINAL CONTROL SYSTEM CAN CONTRIBUTE AN IMPORTANT STEP FORWARD TO IMPROVE PEAK HOUR TRAFFIC FLOW AND TRAFFIC SAFETY ON FREEWAYS.

  • Supplemental Notes:
    • Hpr, Ees-278
  • Corporate Authors:

    Ohio Department of Highways

    Columbus, OH  USA  43210

    Ohio State University, Columbus

    190 North Oval Drive
    Columbus, OH  USA  43210
  • Authors:
    • Treiterer, J
  • Publication Date: 1966

Subject/Index Terms

Filing Info

  • Accession Number: 00203125
  • Record Type: Publication
  • Source Agency: Bureau of Public Roads /US
  • Files: TRIS
  • Created Date: Dec 1 1994 12:00AM