PROBLEMS FACED BY STATE HIGHWAY DEPARTMENTS IN DEVELOPING STATISTICAL SPECIFICATIONS

PROBLEMS WHICH MUST BE FACED BY STATE HIGHWAY AGENCIES IN APPLYING STATISTICAL PRINCIPLES TO HIGHWAY SPECIFICATIONS ARE DISCUSSED. THREE OF THE MAJOR ENGINEERING PROBLEMS IN WHICH STATISTICAL TOOLS CAN BE HELPFUL ARE: (1) ESTABLISHING NUMERICAL SPECIFICATION LIMITS, (2) PROVIDING GUIDELINES FOR PROPER SAMPLING, AND (3) ANALYZING TEST RESULTS. THE BASIC OBJECTIVE OF HIGHWAY SPECIFICATIONS IS TO ASSURE SATISFACTORY PERFORMANCE AT MINIMUM COST. UNBIASED DATA IS NEEDED WHICH DEFINES THE AVERAGE LEVEL, THE OVERALL VARIABILITY, AND THE SOURCES OF VARIABILITY OF THE SELECTIVE CHARACTERISTICS OF MATERIALS AND CONSTRUCTION ITEMS OF ACCEPTABLE QUALITY. TO PREVENT FLAT BIAS, A NON-SUBJECTIVE MEANS OF SAMPLE SELECTION SHOULD BE USED, SPECIFICALLY TABLES OF RANDOM NUMBERS. ASSUMING REALISTIC SPECIFICATION TOLERANCES, STATISTICALLY BASED SAMPLING, MEANINGFUL TEST METHODS, AND ACCURATE TESTING, IT IS THE TEST RESULTS WHICH ARE THE PRIMARY INDICATION OF THE QUALITY OF MATERIAL PRODUCED OR OF THE COMPLETE ITEM OF CONSTRUCTION. SUFFICIENT MAJOR RESEARCH WORK HAS BEEN COMPLETED TO INDICATE BOTH THE PRACTICALITY AND THE ECONOMIC NECESSITY OF THE USE OF STATISTICAL TOOLS IN MANY MAJOR ITEMS IN HIGHWAY SPECIFICATIONS. IT WILL STILL BE NECESSARY TO FOLLOW GOOD CONSTRUCTION PRACTICE, TO HAVE INSPECTORS AT ALL CRITICAL POINTS, AND TO EXERCISE GOOD INSPECTION PRACTICES AND TO CONDUCT EVALUATION TESTS. STATISTICS WILL NOT TELL AN INDIVIDUAL WHAT CORRECTIVE ACTION TO TAKE, BUT WILL HELP TO SHOW WHERE CORRECTIVE ACTION IS NEEDED.

  • Corporate Authors:

    Materials Research & Development Inc

    ,    
  • Authors:
    • Van, TIL CJ
  • Publication Date: 1968-2

Subject/Index Terms

Filing Info

  • Accession Number: 00214810
  • Record Type: Publication
  • Report/Paper Numbers: 8 pp
  • Files: TRIS
  • Created Date: May 24 1994 12:00AM