EARLY EVALUATIONS OF SHRP LTPP DATA AND PLANNING FOR SENSITIVITY ANALYSES

This paper describes the results of two task studies in the SHRP Long Term Pavement Performance (LTPP) program. These are the Data Processing and Evaluation Study, and the Sensitivity Analysis of Explanatory Variables in the National Pavement Performance Data Base. The analyses are to be conducted individually for each of 8 General Pavement Studies (GPS). Expected products from the data analysis are also presented, together with their potential impacts on pavement design and management. As the LTPP data base represents a resource of major importance to the international highway community, its "completeness" and the identities of missing data elements will be of interest. The distributions of the data elements are not only of importance to the effectiveness of the analyses, but offer useful information in themselves. The assessment of "relative significance" of data elements are being made by selected experts. The assessments will be in terms of three levels of significance - clearly significant, moderately significant, and little or no significance. As the relative levels assigned to specific data elements will represents the accumulated experience of recognized experts, they represent current knowledge of pavements and will be of interest to highway professional. The analytical procedures under development for the sensitivity analyses will represent the state-of-the-art for such studies, so other researchers will wish to know details of the procedures to be applied. Identification of what may and may not be expected from these early analyses is expected to be major interest, as well as how these products may be expected to impact highway practice. For the covering abstract of the conference see IRRD no 860147