Precision Estimates of AASHTO T 242

This report presents results of the study to prepare precision estimates for AASHTO T 242, “Frictional Properties of Paved Surfaces Using a Full-Scale Tire.” The data used in this study were provided by Texas Transportation Institute (TTI) and Transportation Research Center (TRC) from evaluation of state friction measurement systems that have been calibrated at their field test centers. Two sets of data were analyzed from each test center: “Initial” or “Arrival” and “Final” or “Departure“. The Initial set was collected by state systems as they arrived to each center for calibration. The Final set was collected after adjustments were made to the state systems to put them into compliance with AASHTO T 242. The variability of the friction measurements were examined for both Initial and Final systems to evaluate the effect of calibration on variability of the measurements. Only the Final State System data were used to determine the precision estimates for measuring frictional properties of paved surfaces. A draft precision statement for AASHTO T 242 is proposed and included in this report.


  • English

Media Info

  • Media Type: Web
  • Edition: Contractor Final Report
  • Features: Appendices; Figures; References; Tables;
  • Pagination: 91p
  • Serial:
  • Publication flags:

    Open Access (libre)

Subject/Index Terms

Filing Info

  • Accession Number: 01141656
  • Record Type: Publication
  • ISBN: 9780309429771
  • Report/Paper Numbers: NCHRP Project 09-26A
  • Files: TRIS, TRB, ATRI
  • Created Date: Oct 6 2009 3:42PM