Development of Texas Mechanistic-Empirical Flexible Pavement Design System (TxME)

The FPS design system implemented in the mid-1990s has limitations in that it does not use any results from laboratory testing so it is impossible to determine benefits from improved base materials or superior asphalt mixes. The development of the new flexible pavement design system. TxME, will enable Texas Pavement designers to take full advantage of new or premium materials, with a full consideration of the influential factors including pavement structure, traffic loading, and environmental conditions. The features of TxME include 1) Mechanistic-Empirical modeling, 2) performance-based material characterization, 3) traffic load spectrum incorporation, 4) design input variability-based reliability methodology, 5) incremental distress prediction, 6) fast running speed. 7) user-friendly interface, and 8) convenient connection with FPS. This report documents the work and findings during this study. Sensitivity analysis shows that TxME can make rational predictions under different combinations of pavement structure, climate, and traffic load. As a first stage, the researchers recommend that TxME be used as a performance check tool for design options recommended by the FPS design system. More calibration and model fine-tuning work still needs to be done.