Over the past decade, the design of both flexible and rigid pavements has been fundamentally evolving. This evolution includes the replacement of empirical design procedures, mainly based on different editions of the American Association of State Highway and Transportation Officials (AASHTO) Design Guide with mechanistic-based procedures, such as the Mechanistic Empirical Pavement Design Guide (MEPDG). This book includes my master thesis that I carried out at University of Alberta, Edmonton, Canada. This book attempts to explore the implementation of the Mechanistic Empirical Pavement Design Guide (MEPDG) in Canada. The content of this book can be categorized into two parts. First, it explores the effects of climate on pavement performance using the MEPDG. Second, it compares the MEPDG with AASHTO – 1993 based Alberta Transportation Pavement Design (ATPD) method. This book presents three novel methods to evaluate the quality of the climatic data files used for the MEPDG. This book also demonstrates the sensitivity of climatic factors on pavement performance. A typical flexible pavement section and climatic data files of different Canadian weather stations were used in this study.