ROAD METER OUTPUT AND ITS CORRELATION WITH PANEL RATINGS IN SASKATCHEWAN

ATTEMPTS TO OBTAIN A SYSTEMATIC MEASURE OF PAVEMENT PERFORMANCE BEGAN IN SASKATCHEWAN IN THE EARLY 1950'S BY PANELS OF EXPERTS WHO RATED THE PRESENT PERFORMANCE RATING (PPR), SINCE RENAMED THE RIDING COMFORT INDEX (RCI). IN THE SPRING OF 1971 THE PROVINCIAL DEPARTMENT OF HIGHWAYS AND TRANSPORTATION PURCHASED A PCA ROAD METER, WHICH IT CALLS THE CAR ROAD METER (CRM), WHOSE BASIC DESIGN AND VEHICLE MOUNTING ARE DESCRIBED. A CORRELATION PROGRAM WAS UNDERTAKEN IN WHICH THE RCI WAS DETERMINED FOR SEVERAL SECTIONS OF HIGHWAY, REPLICATE RUNS WERE MADE DURING THE SAME WEEK WITH THE CRM UNDER "STANDARD" CONDITIONS, AND THE CRM RUNS WERE THEN REPEATED WITH THE CONDITIONS VARIED. THE RCI PANELS EMPLOYED 16 PERSONS, FOUR IN EACH PANEL. AMONG THE VARIABLES STUDIED WERE THE EFFECT OF CRM UNIT SPEED ON RCI ESTIMATES, THE EFFECT OF VEHICLE LOAD ON CRM UNIT OUTPUT, THE EFFECT OF TIRE-PRESSURE VARIATIONS ON THE CRM UNIT, AND THE EFFECT OF TEMPERATURE ON THE CRM UNIT. FROM THE FIVEFOLD REPLICATION OF CRM TESTS IT WAS FOUND THAT THERE IS AN INCREASE IN STANDARD DEVIATION WITH AN INCREASE IN THE SUMMATION OF COUNTS. THE CORRELATION COEFFICIENTS OF THESE CURVES ARE LOW BUT GIVE AN INDICATION OF WHAT REPEATABILITY MAY BE EXPECTED UNDER VARYING CONDITIONS. THE FOLLOWING CONCLUSIONS WERE REACHED: (1) ALL THE LISTED VARIABLES HAD AN EFFECT ON THE ABILITY OF THE CRM TO PREDICT RCI AND SHOULD THEREFORE BE CONTROLLED, ESPECIALLY WHEN TESTING PAVEMENTS WITH HIGH RCI VALUES. (2) THE HIGHEST ACCURACY IN ASSESSING PAVEMENTS WITH A HIGH RCI IS ACHIEVED AT A VEHICLE SPEED OF 40 MPH. (3) WHEN ASSESSING PAVEMENTS WITH A RELATIVELY HIGH RCI, REPLICATE TESTS SHOULD BE PERFORMED WHERE ACCURACY IS IMPORTANT. (4) ALTHOUGH THE STANDARD DEVIATION OF THE CRM OUTPUT INCREASED WITH DECREASING RCI, ITS SENSITIVITY FOR PREDICTING RCI INCREASED BECAUSE OF THE LOGARITHMIC RELATION.

Media Info

  • Media Type: Print
  • Features: Figures; References; Tables;
  • Pagination: pp 77-90
  • Monograph Title: PAVEMENT EVALUATION USING ROAD METERS
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00207537
  • Record Type: Publication
  • Files: TRIS, TRB, ATRI
  • Created Date: May 21 1973 12:00AM