This study focuses on the current strength evaluation policies for strength assessment of corroded steel girders and investigates potential improvements based on real corrosion data. The research work included in this report has three phases. First, the current deterioration condition of steel bridges is studied through MassDOT inspection reports of bridges with beam end corrosion. The topology and the extent of the phenomenon are recorded from the reports and the gathered data are processed to define the most common corrosion patterns. Second, full scale experimental testing of naturally corroded girders is performed. The beams are obtained from bridge demolition projects across the Commonwealth of Massachusetts and tested in the Brack lab at UMass Amherst. Based on the experimental test results, a numerical finite element model is appropriately calibrated to predict the failure load of corroded beam ends. Finally, combining the new corrosion patterns identified during the first part of the work with finite element modeling, an extensive parametric analysis is performed. Based on the numerical outcome, the current procedures are evaluated and improvements are proposed through a new set of equations. The report includes many important findings regarding the behavior of corroded beam ends and discusses the limitations of this study and potential future research work.