A Review of PMED Local Calibration Efforts for Flexible and Rigid Pavements

The AASHTOWare Pavement Mechanistic-Empirical Design (PMED) significantly improved from the empirical American Association of State Highway and Transportation Officials (AASHTO93) design methodology. The PMED transfer functions are calibrated nationally using long-term pavement performance data. It is recommended that these PMED transfer functions be calibrated to adapt to local conditions. Several studies have calibrated these transfer functions. This paper summarizes different calibration efforts for flexible and rigid pavements. The number of pavement sections, PMED versions, performance models, and input levels used in various studies have been reviewed. This paper also summarizes the development and adoption of PMED in different states. Moreover, it also discusses the calibration challenges, the locally calibrated transfer function coefficients, and the sensitivity of these coefficients to performance prediction. The results show that the PMED global models under- or over-predict the performance; therefore, they cannot be used for local conditions. Local calibration significantly improves the performance predictions. The significant calibration challenges include limitations to performance data and the number of sections. Some studies have also shown consistency issues with flexible pavements’ thermal and top-down cracking models. Pavement design is an essential part of the calibration process. The PMED design thicknesses are slightly lower compared to AASHTO93 for both flexible and rigid pavements. Overall, this review can be helpful to practitioners in any future calibration efforts.