Truck size and weight are regulated differently in every country with various levels of restrictiveness for the primary purpose of protecting highway infrastructure. There is now a trend to move towards performance based standards (PBS) where size and weights are regulated based on the vehicles performance requirement and interaction with the traffic and infrastructure rather than fixed values. A “bridge formula” is a variation of performance based standards, where it regulates parameters (axle spacing and number of axles) that are related to the performance of the vehicle in terms of the load effect imposed on bridges and pavements. Bridge formulae provide an efficient method to help with the regulation of truck weights while ensuring the sustainability of the infrastructure by allowing vehicle configurations that have an acceptable effect on structures. This paper presents the findings of a comprehensive literature review to identify and compare existing bridge formulae used around the world. From the knowledge gained from previous research and experience in the literature, issues with existing bridge formulae are identified and the opportunity to develop and implement a European bridge formula for the regulation of truck size and weights in Europe is considered.
