PAVEMENT DESIGN AND THE DECISION-MAKING PROCESS

The history of pavement design is briefly reviewed, and development in and future prospects for utilizing systems engineering in the decision-making process is discussed. Pavement design has evolved from the use of standard sections of different categories of soil, climate, and traffic conditions to that of empirical relationships between structural designs, materials, traffic, climate, and subgrade conditions based on test programs such as the AASHO Road test. Recently, interest has been expressed in the concept of total cost analysis. A Systems Analysis Model for Pavements (SAMP5) is one approach to considering initial construction, operationa, and user costs in the decision making process. The SAMP6 program (an improvement of SAMP5) requires 12 classes of variables: program control and miscellaneous; environmental (2) and serviceability (3) traffic and reliability (2); constraint; traffic delay; maintenance; cross-section, cost model and shoulder; tack coat, prime coat, bituminous materials; wearing surface, overlay, pavement material; and shoulder layer material. The SAMP6 program operation normally considers between 1,000 and 2,000 different trial designs. The output of the SAMP6 is provided in 3 parts: summary of input data; summary of the best design strategy for each material and larger combination; and the best design strategy in order of increasing total cost per square yard of traffic lane. Illustrations of the application of SAMP6 include a comparative study of the economics of staged construction and planned rehabilitation versus the "no-overlay" or strong initial construction approach, and a study of the effect of fluctuating material costs on optimum design. The operational SAMP6 program provides decision-makers with the capability of comprehensively selecting optimum strategies and updating decisions as conditions change.

  • Supplemental Notes:
    • Proceedings from a conference on Utilization of Graded Aggregate Base Materials in Flexible Pavements, March 25-26, 1974, Oak Brook Hyatt House, Oak Brook, Illinois.
  • Corporate Authors:

    National Crushed Stone Association

    1415 Elliot Place, NW
    Washington, DC  United States  20007

    National Sand and Gravel Association

    900 Spring Street
    Silver Spring, MD  United States  20910

    National Slag Association

    300 South Washington Street
    Alexandria, VA  United States  22314
  • Authors:
    • SMITH, H A
  • Publication Date: 1974

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Filing Info

  • Accession Number: 00127527
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Apr 7 1976 12:00AM