Flexible pavement condition model using clusterwise regression and mechanistic-empirical procedure for fatigue cracking modeling.

摘要

Pavement condition prediction modeling is a critical component of a pavement management system (PMS). Accurate prediction models assist agencies in performing cost-effective maintenance or rehabilitation at the proper time, thus most efficiently improving the overall pavement condition under specific budget limits.; The accuracy of a prediction function is dependent on data availability and the modeling method that is employed. The family method, which groups pavements into families and then fits data to a prediction function within each family using the ordinary least squares (OLS) regression method, may result in prediction functions with large scatters, i.e., low predictive accuracy. In this study, a method called clusterwise regression was proposed to be employed to predict the pavement condition ratings (PCR). The clusterwise regression simultaneously determines clusters (families) and corresponding prediction functions. In order to make this method practical, a modification was made by estimating membership of a data point to a cluster utilizing its error terms. An application of the modified clusterwise regression was proposed to predict PCR of future years by directly utilizing the result of the modified clusterwise regression. The results of the study show that the proposed procedure improved the accuracy of predictions from that of the family method. The prediction equations of PCR for flexible pavements in Ohio have been developed.; A simplified mechanistic-empirical based probabilistic method was also used to model one of the major distress types of flexible pavement, that of fatigue cracking. The categorical fatigue cracking ratings were first converted to numerical values. The regression coefficients in the model were then determined by minimizing the differences between the measured and predicted fatigue cracking areas. The estimated fatigue cracking model can predict the occurrence of fatigue cracking for any specified percentage. However, the limited data available from the database restricts the accuracy of the calibrated model.