Enhancing MEPDG distress models prediction for Saudi Arabia by local calibration

During the development of pavement design methods, the MEPDG is evolved by NCHRP 1-37 project. This reason led the roadway agencies to implement the MEPDG. To implement MEPDG, the local calibration is necessary to increase the accuracy of distress models used in MEPDG to predicted pavement performance, because these models were derived depending on the conditions of the United States. This study aims to the calibration of MEPDG based on the conditions of Riyadh, Saudi Arabia. The rutting and IRI models were calibrated using an optimization approach embedded in MS Excel (namely, solver optimization). The study results reveal that the adjusted coefficients are appropriate for this study because the new coefficients of the rutting models reduced the bias from 4.90 to 0.03 and SSE from 317.68 to 61.71 while the new coefficients of the IRI model reduced the bias and SSE from 0.44, 0.31 to 0, 0.03 respectively.