California has more climatic and material type variations than any other state in the United States . The proposed AASHTO 2002 Pavement Design Guide does not cover the majority of distresses occurring on Caltrans rigid pavement systems. Research has begun to develop a supplemental concrete pavement design process, which predicts fatigue cracking at transverse joints and along the longitudinal edge. The transverse joint fatigue algorithm will allow for design of a concrete pavement at any location in California , given a set of input parameters such as traffic, material properties, and slab geometry. An existing finite element program is being used to calculate the critical pavement responses and reduce the complexity of problems due to the wide range of conditions in California . This research project will improve the design of rigid pavement highways in California and will supplement the existing national standards for design concrete pavements.