Verification of Virtual Climatic Data in MEPDG Using the LTPP Database

Abstract

The Enhanced Integrated Climatic Model (EICM) integrated in the Mechanistic-Empirical Pavement Design Guide (MEPDG) allows users to select adjacent weather stations to generate a virtual weather station (VWS), whose data are further used to predict environmental impact on pavement performance. It is essential that the derived virtual data be accurate and representative of the actual climatic conditions. To evaluate the accuracy of the MEPDG generated VWS data, climatic data from corresponding automated weather stations (AWS) in the long-term pavement performance (LTPP) database are obtained to conduct the comparison analysis. It is observed that most VWS climatic data estimate the actual weather data reasonably well. However, in some cases, significant differences are observed. The potential factors resulting in the discrepancies are investigated. MEPDG analyses are conducted to quantify the climate data differences on predicted pavement performance. Finally, the paper presents recommendations when using the MEPDG software to generate VWS so as to help establish more accurate key climatic inputs.