Strategic Plan for Implementing Mechanistic-Empirical Pavement Design Guide in Iowa

With the release of the new Mechanistic-Empirical Pavement Design Guide (MEPDG), pavement design has taken a “quantum” leap forward. It is clear that the basis of the current empirically-based AASHTO pavement design procedures are no longer applicable to current conditions in Iowa. The Iowa Department of Transportation (Iowa DOT) will significantly benefit by implementing the MEPDG as a reliable pavement performance prediction tool. The major benefits of adopting the MEPDG are long-term which include (1) more appropriate designs focusing on minimizing or mitigating the predominant distress types that occur in Iowa, (2) better performance predictions resulting in significant long-term savings by eliminating the possible premature failures and over-designing the pavement sections, (3) better materials-related research reducing the need to conduct extensive, lengthy, and costly field trials, and (4) the use of MEPDG software as a powerful forensic tool for analyzing the condition of existing pavements. In order to effectively and efficiently transition to the MEPDG, the Iowa DOT needs a detailed implementation and training strategy. In support of the MEPDG implementation initiatives, sensitivity studies were conducted using the MEPDG software to identify design inputs pertaining to both rigid pavements and flexible pavements that are of particular sensitivity in Iowa as well as those factors that are of no particular sensitivity. Based on a study of the MEPDG design components, the results of sensitivity analyses and past experience, a strategic plan for implementing the MEPDG in Iowa is presented.