Abstract
Aggregate pavement condition indices are used by many agencies in the United States and abroad to select maintenance strategies and program network rehabilitation strategies. These indices are usually calculated as weighted sums of several individual damage measurements such as length of transverse cracks, rut depth, and roughness. Existing approaches to condition index calibration are reviewed and a statistical procedure for developing pavement condition indices from distress measurements using factor analysis is described. This method is used to re-estimate a condition index from the data collected in the AASHO Road Test for calibration of the present serviceability index (PSI). The new index is compared with the PSI.