Effects of Subgrade Resilient Modulus and Climate Inputs on MEPDG

Local validation and calibration are essential steps before the local implementation of the newly developed Mechanistic-Empirical Pavement Design Guide (MEPDG). Recently, a comprehensive study was carried out in Louisiana to validate and calibrate the MEPDG models using the network-level pavement management performance data. After comparing the measured and predicted pavement performance, a set of Louisiana global prediction errors were obtained for each distress type. Statistical analyses were then performed to evaluate if the MEPDG prediction errors are affected by the inputs of subgrade resilient modulus and climate conditions (i.e., geographic location and groundwater table depth). The MEPDG prediction errors for two types of distresses (fatigue cracking and rutting) were considered in this study. To cancel out the effect of pavement structure, projects with different pavement structures were sampled in balance in each group. Hypothesis tests were applied to evaluate if significant difference exists among the mean MEPDG prediction errors of each randomly sampled group of projects. Finally, the results were interpreted with respect to the local conditions and practice in Louisiana.