The safety of existing slab-between-girder bridges is subject to discussion in the Netherlands. Current design codes are conservative for shear-critical girders, and nonlinear finite element analysis is considered a more accurate assessment method. This paper investigates if the Dutch guidelines for nonlinear finite element analysis, which were largely based on laboratory experiments, can safely predict the behavior of large-scale shear-critical post-tensioned girders. The simulation results are compared with experimental observations on girders taken from a demolished bridge (the Helperzoom bridge) after serving for more than 50 years. Predicted and experimentally observed material properties are used as inputs for numerical models. For both, safe predictions of inclined cracking and ultimate capacities are obtained. Parameter studies for load positions and prestress levels are also performed to get a deeper insight into the structural behavior of such girders. This work shows that the guidelines can be used for assessment.