Evaluation and Improvement of the CRS Prediction Models

The Illinois Department of Transportation (IDOT) measures pavement deterioration using Condition Rating Survey (CRS) values. CRS is a rating scale that ranges from 1 to 9; a newly build or resurfaced pavement is assigned a value of 9. The CRS is a function of key distress types in each pavement type. The ILDOT is continuing its effort to build a model that is able to predict the future CRS values as accurately as possible. Two different CRS prediction models were previously developed for this purpose; multiple regression and single slope (linear). The primary goal of this report is to evaluate these two prediction models and to improve their prediction capabilities if possible. The validity of the models was tested using the data of in-service pavements retrieved from the IPFS database. The two models were also evaluated from the perspective of pavement design and analysis principles. After these evaluations were conducted, the single slope method was found to be deficient in that there actually exists two distinct slopes in CRS over time for a given section. A generally steeper slope from a CRS of 9 to about 6.5, and a second flatter slope from 6.5 to 1. Recommendations for these slopes were developed.

  • Corporate Authors:

    University of Illinois, Urbana-Champaign

    Department of Civil and Environmental Engineering
    205 North Mathews Avenue
    Urbana, IL  United States  61801-2352

    Illinois Department of Transportation

    Bureau of Materials and Physical Research
    126 East Ash Street
    Springfield, IL  United States  62704-4766

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Authors:
    • Gharaibeh, Nasir G
    • Darter, Michael I
    • Heckel, Laura B
  • Publication Date: 1999-3


  • English

Media Info

  • Media Type: Web
  • Edition: Project Report
  • Features: Figures; References; Tables;
  • Pagination: 47p

Subject/Index Terms

Filing Info

  • Accession Number: 01108755
  • Record Type: Publication
  • Report/Paper Numbers: FHWA-IL-UI-267, UILU-ENG-99-2004
  • Contract Numbers: IHR-540
  • Created Date: Aug 11 2008 11:22AM