The global motorway network is currently experiencing substantial growth, leading to a constant expansion of engineering structures, with bridges being a particular focus. Due to the enormous investments made, it is crucial that we not only preserve their value but also enhance them to meet future requirements. The growth of road traffic has become a major concern due to the increasing number of vehicles and the tonnage carried per axle. Future needs are also expected to follow the same trend. This surge in tonnage will escalate and may have serious repercussions on the stability of road bridges. Given that the computations for pre-existing bridges were conducted in agreement with the national regulations in force before their building, it is crucial to scrutinise the safety response of these bridges with regard to the amplified loads of heavy goods vehicles in circulation. The article aims to compare the various distortions that occur in the concrete multiple girder bridge slabs under the current regulations and the growing weight of lorriespresently operating by taking Algeria as a case study.