The article discusses the findings of a study focused on evaluating the load-bearing capacity of road bridge superstructures that are designed based on standard models widely adopted in the Russian Federation and Vietnam. The research reveals that the shift from the traditional allowable stress design method to the more modern limit state design method now implemented in current engineering standards plays a key role in explaining why the actual load-bearing capacity of these bridge superstructures is substantially greater than the loads anticipated during the original design phase. This transition in design methodology accounts for a more realistic and conservative assessment of structural performance, ultimately resulting in safer and more resilient bridge constructions.