Identifying and modelling permit trucks for bridge loading

Accurate estimates of characteristic traffic load effects are essential in order to optimise bridge safety assessment. Permit trucks dominate the extreme upper tail of the truck loading distribution and as a result need careful examination. This paper proposes rules for filtering these trucks from weigh-in-motion data for both the USA and Europe. The importance of these trucks in critical bridge loading events is then examined for both regions. A Monte Carlo traffic simulation model is developed, which focuses on the accurate simulation of permit trucks.