Traffic loads for the assessment of existing bridges

IABSE TG 1.3 aims to identify appropriate approaches for applications of the partial factor format in assessment of existing bridges. A sub-group was formed to investigate and provide recommendations on updating road traffic loads. Commonly, these are assessed by complex numerical simulations. While this study does not provide a universal solution, it demonstrates by a case study a simple and reasonably conservative way of using simulations to update traffic load effects, meanwhile continuously highlighting the objectives, potential alternatives or pitfalls of simulations. The results indicate that, for the short, single span bridge under consideration, the characteristic values given in Eurocodes provide conservative estimates. The probabilistic model for traffic loading obtained by bridge- and route-specific simulations will yield substantially more favourable reliability levels in comparison to the general model in fib Bulletin 80.