A comparative study of a bridge traffic load effect using micro-simulation and Eurocode load models

Micro-simulation, a process by which individual vehicles and driver behaviour are simulated, is used in this study to assess the effects of congested traffic load on bridges. The Eurocode for traffic loading on long-span bridges was derived from simulations of convoys of trucks at small bumper-to-bumper distances. Real congested traffic includes a mix of cars and trucks with a variety of congestion patterns, which reduce the load effects. Micro-simulation is used in this study to generate more realistic traffic loading scenarios, based on real traffic data from a Polish site. The results are then extrapolated to determine characteristic maximum effects for two return periods. The Eurocode is shown to be conservative, and micro-simulation based assessment is therefore valuable for problem long-span bridges.