Due to the massive increase in traffic volume and in permissible vehicle loads over the recent decades, increases in normatively applied traffic loads have occurred. Furthermore, the calculation of the resistance changed over time. If such a structure has to be recalculated according to the current normative situation, deficits in the shear capacity often occur. At the Institute of Structural Engineering (Department for Structural Concrete, Vienna University of Technology), a zone-based detection method was developed for the purpose of a more accurate and realistic assessment of the shear strength of prestressed concrete bridges. In the context of this diploma thesis this model is used to recalculate the existing bridge over the Wangauer Ache. At the beginning of this thesis, the procedure of a recalculation of bridges as well as the currently applicable normative calculation methods are explained. Thereafter the zone-based model developed by P. Huber at the Institute of Structural Engineering and the further developed engineering model for multi-field bridges will be presented. Subsequently, the shear capacity of the bridge is calculated considering the valid calculation guideline ONR 24008 according to Eurocode 2 and fib Model Code 2010 and afterwards considering the verification concept according to P. Huber. The calculations show that the shear capacity of the main girders is by far not sufficient for either a Eurocode or a fib Model Code 2010 calculation to give a positive proof. The zone-based detection method allows on the one hand to take account of the expected crack formation and on the other hand to take account of additional bearing components, which allows a more realistic verification. As a result, the utilization rates with regard to a lateral force are greatly reduced and a positive transverse force detection can be performed in almost all areas. Furthermore, it was found in the course of the recalculation that there are problems in the verification of the transverse force carrying capacity of the reinforced concrete carriageway slab. A scientific study of the shear capacity of such plates is also currently a possible field of research. The application of the zone-based detection method offers the engineers a very good possibility of realizing the shear capacity. Since there are many existing prestressed concrete bridges with similar problems, the potential of this detection method is enormous. By applying the concept, it will be possible in many cases in the future to be able to dispense with expensive shear reinforcements.