Local Calibration of the MEPDG Using Test Track Data

Abstract

The Mechanistic-empirical Pavement Design Guide (MEPDG), now known as AASHTOWare Pavement ME Design, is a state-of-art mechanistic-empirical design method. It has been adopted by the American Association of State Highway and Transportation Officials (AASHTO) as the new standard for pavement design in the U.S. However, the MEPDG was calibrated to various types of pavements located across the country representing diverse design conditions. Since the default transfer functions were nationally-calibrated, the performance prediction for local projects sometimes may not correlate well with the local performance measurements. The National Center for Asphalt Technology (NCAT), equipped with a full-scale accelerated Test Track, supported the evaluation and local calibration of the nationally-calibrated models. The study results showed the nationally-calibrated fatigue cracking model and the IRI model matched the measured values in the 2003 research cycle, and no better coefficients were found to improve the model predictions. However, applying the same fatigue coefficients to the 2006 research cycle resulted in poor correlations to measured performance and no significant improvement to fatigue cracking prediction was found. The nationally-calibrated rutting model over-predicted rut depths, but the accuracy of the rutting model was significantly improved by local calibration. The research methods and findings may be useful for the transportation agencies to perform local calibration studies.