Prestressed concrete is one of the most common materials used in modern bridge construction. Nearly 50% of new highway bridges are constructed of prestressed concrete. Current U.S. bridge design codes do not allow cracking under service load in prestressed concrete members Partially prestressed concrete is a type of concrete construction in which some prestressing force is applied to the steel reinforcement. For the purposes of this study, partial prestressing will be considered as prestressed concrete in which cracking is allowed under service loading. This cracking increases the possibility of fatigue failure of the member under repetitive loading, such as that encountered by bridge structures The purpose of this project is to develop an analysis model to predict the fatigue life of bonded, pretensioned, partially prestressed concrete girders carrying highway traffic loadings. This study is analytical, with data on the fatigue behavior of partially prestressed concrete beams coming from earlier tests by other researchers This project begins by reviewing some of the earlier research on partially prestressed concrete beams, fatigue properties of concrete, reinforcing steel and prestressing strand, and highway bridge loadings. An analytical model of the behavior of a partially prestressed beam under fatigue loading is developed. Time-dependent factors such as creep, shrinkage, and prestressing steel relaxation are included in the analysis. Cumulative damage to the prestressing strand and reinforcing steel is calculated using Miner's rule. With this cumulative damage result, the fatigue life of the girder is predicted. The fatigue analysis model is verified using the results of laboratory constant and variable amplitude fatigue tests An example series of partially prestressed girders is designed and analyzed under highway loading using the fatigue analysis model Only flexural behavior is considered in this report. Shear fatigue is not included in this investigation