DETERMINATION OF TRAFFIC PARAMETERS FOR THE PREDICTION, PROJECTION, AND COMPUTATION OF EWL'S FINAL REPORT

THE CONCEPT OF EQUIVALENT WHEEL LOAD (EWL) OR LOAD EQUIVALENCY FACTORS WAS INVESTIGATED AS A MEANS OF TRAFFIC EVALUATION OF PAVEMENT-THICKNESS DESIGN PROCEDURES. THIS STUDY WAS BASICALLY A TRAFFIC STUDY TO: (1) ESTABLISH A PROPER METHODOLOGY FOR OBTAINING ESTIMATES OF DESIGN EWL'S, (2) IDENTIFY THOSE CHARACTERISTICS OF A PARTICULAR ROUTE OR LOCALE WHICH AFFECT THE COMPOSITION AND AXLELOAD DISTRIBUTIONS OF TRAFFIC, (3) DEVELOP A MEANS FOR RELATING SIGNIFICANT TRAFFIC PARAMETERS TO LOCAL CONDITIONS, AND (4) PROVIDE A MEANS WHEREBY ESTIMATES OF EWL'S BY BOTH THE KENTUCKY AND AASHO PROCEDURES CAN BE COMPARED AND THE DIFFERENCES EVALUATED. PREDICTIVE PROCEDURES FOR COMPARING ALTERNATE PREDICTIVE PROCEDURES INCLUDE THE FOLLOWING: (1) THE PREDICTIVE MODEL SHOULD CONSIDER AS MANY OF THE RELEVANT LOCAL CONDITIONS WHICH DETERMINE THE COMPOSITION AND WEIGHTS OF THE TRAFFIC STREAM AS POSSIBLE, (2) THE PREDICTIVE MODEL SHOULD MAKE FULL USE OF ALL AVAILABLE VEHICLE CLASSIFICATION AND WEIGHT DATA, AND (3) THE PREDICTIVE MODEL SHOULD POSSESS THE QUALITIES OF SIMPLICITY, REASONABLENESS, PREDICTIBILITY, AND ACCURACY. THE LOCAL CONDITIONS WHICH WERE FOUND TO SIGNIFICANTLY AFFECT THE TRAFFIC PARAMETERS INCLUDED ROAD TYPE, DIRECTION, ALTERNATE ROUTE, SERVICE PROVIDED, TRAFFIC VOLUME, MAXIMUM ALLOWABLE GROSS WEIGHT, GEOGRAPHICAL AREA, YEAR, AND SEASON. ANALYSES WERE MADE TO FIND A SUITABLE EMPIRICAL METHOD FOR PREDICTING THE TRAFFIC PARAMETERS ON THE BASIS OF AN ANALYSIS OF THE PERTIMENT LOCAL CONDITIONS. THE CHOSEN METHOD FOR PREDICTING VEHICLE-TYPE PERCENTAGES CONSISTS OF A SET OF BASIC PERCENTAGES DETERMINED JOINTLY BY ROAD TYPE, VOLUME, AND MAXIMUM ALLOWABLE GROSS WEIGHT AND A A SERIES OF MULTIPLICATIVE CORRECTION FACTORS DETERMINED INDEPENDENTLY BY DIRECTION, SEASON, ALTERNATE ROUTE, SERVICE PROVIDED, AND GEOGRAPHICAL AREA. THE CHOSEN METHOD FOR PREDICTING UNIT EWL'S IS BASED ON A MULTIPLE REGRESSION MODEL THAT CONSIDERS ALL OF THE ABOVE LOCAL CONDITIONS, EXCEPT YEAR, SEASON, AND SERVICE PROVIDED, IN AN ADDITIVE FASHION. THE RECOMMENDED METHODOLOGY WAS FOUND TO PROVIDE A SUITABLE MEANS FOR PREDICTING EWL ACCUMULATIONS.

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  • Supplemental Notes:
    • Kyhpr-64-21: HPR-1 (4), 116 PP, 18 FIG, 18 TAB, 7 APP
  • Corporate Authors:

    Kentucky Department Highways

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  • Authors:
    • Deacon, J A
    • Lynch, R L
  • Publication Date: 1968-8

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Filing Info

  • Accession Number: 00205738
  • Record Type: Publication
  • Files: TRIS, STATEDOT
  • Created Date: Jan 31 1994 12:00AM