Studies conducted in Arkansas, Idaho, Minnesota, New Jersey, and Ohio report issues in matching the predictions from the Enhanced Integrated Climatic Model (ECIM) for moisture contents with field observations. LTPP has recently encountered issues in trying to translate the SHRP PG binder grades designations to locations outside of the continental United States using algorithms developed in North America. FHWA is also using simplified versions of Mechanistic-Empirical Pavement Design Guide (MEPDG) pavement performance prediction models to predict changes in the National Highway System based on HPMS data inputs and very coarse climate inputs to the simplified models.
The overall objective of this project is to develop simplified models of climate impacts on pavement performance-prediction models that can be implemented by local, state, and federal agencies in their asset and pavement management systems. Some of the issues to be investigated include: (1) evaluation of the impact of using the complete suite of current Modern-Era Retrospective Analysis for Research and Applications (MERRA) grid data that includes direct use of solar radiation inputs to predict pavement temperature, versus use of empirical relationships embedded in applications like the MEPDG and LTPPBind; (2) evaluation of the impact of using MERRA data for civil engineering applications that require hourly climate inputs; (3) evaluation of the use of MERRA data in calibration of the unbound material models used in the MEPDG; and (4) recommendations on the use of MERRA data in each of the evaluated engineering applications. If the MERRA 2 data set is available at the time of study, recommendations on the potential impact and difference of approach in using the two data sets (MERRA and MERRA 2) will be evaluated.