CORRELATION OF THE IJK ROADMETER TO THE INTERNATIONAL ROUGHNESS INDEX. FINAL REPORT

The Iowa Department of Transportation has been determining a present serviceability index (PSI) on the primary highway system since 1968. A CHLOE profilometer has been used as the standard for calibrating the Roadmeters that do the system survey. The current Roadmeter, an IJK Iowa DOT developed unit, is not considered an acceptable Roadmeter for determining the FHWA required International Roughness Index (IRI). Iowa purchased a commercial version of the South Dakota type profiler (SD Unit) to obtain IRI. This study was undertaken to correlate the IRI to the IJK Roadmeter and retire the Roadmeter. One Hundred forty-seven pavement management sections (IPMS) were tested in June and July 1991 with both units. Correlation coefficients and standard error of estimates were: PCC pavements - r-squared 0.81 and Std. Error 0.15; Composite pavements - r-squared 0.71 and Std. Error 0.18; and ACC pavements - r-squared 0.77 and Std. Error 0.17. The correlation equations developed from this work will allow use of the IRI to predict the IJK Roadmeter response with sufficient accuracy. Trend analysis should also not be affected.

Media Info

  • Features: Appendices; Figures; References; Tables;
  • Pagination: 29 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00621720
  • Record Type: Publication
  • Report/Paper Numbers: MLR-91-5
  • Files: TRIS, STATEDOT
  • Created Date: Apr 30 1992 12:00AM