Analysis of Site-Specific MEPDG Traffic Inputs Parameters for the State of Tennessee in Comparison to National Inputs

Traffic inputs for Mechanistic Empirical Pavement Design Guide (MEPDG) provides necessary information in terms of traffic load distributions, intensity and number of traffic load repetitions. The MEPDG requires more traffic data input than the AASHTO design guide, which makes switching to the new design guide a challenge to some states DOT's. According to MEPDG, data inputs are a hierarchical as level 1, 2 and 3. Level-1 is site-specific data, level-2 is regional or statewide data, and level-3 is national wide data. This study compares the design output using site specific traffic input data to the design output using national default values. The analysis uses data collected and processed by Long Term Pavement Performance and measured distresses by Tennessee DOT. It was found out that the national wide inputs values overestimates the distresses. Also the site specific traffic input predicts more economical pavement sections than national wide although both input values estimate more economical designs than AASHTO-1993.