Changes to the Mechanistic-Empirical Pavement Design Guide software through version 09.00, July 2006

This digest summarizes numerous changes made under National Cooperative Highway Research Program (NCHRP) Project 1-40D to the original Version 0.7 of the "Mechanistic-Empirical Pavement Design Guide" (MEPDG) software delivered under NCHRP Project 1-37A in July 2004. Specifically, the digest describes the corrections incorporated in Version 0.8 (released in November 2005) and the mainly technical improvements and enhancements included in Version 0.900 (released in July 2006). Changes in Version 0.900 include software changes in general (including changes to traffic and other general topics), as well as changes in the integrated climatic model, in flexible pavement design and analysis, and in rigid pavement design and analysis.