This report documents a study undertaken to conduct a detailed review of the distress data collected for the Long-Term Pavement Performance (LTPP) project. As a result of this work, a more in-depth review of the distress data has been completed and it has improved the understanding of the compatibility of distress data collected using different methodologies to facilitate future analysis. As a result of this study, it was found that distress data collected from the three different methodologies for LTPP may be combined without concern for systematic differences between the data sets.

This report will be of interest to highway agency engineers involved in the collection, processing, and interpretation of cracking data for the purpose of pavement management.