Load effect of multi-lane traffic simulations on long-span bridges

The traffic loading of long-span bridges is governed by congestion. Real-world observations show that congestion can take up different forms. Nevertheless, most previous studies on bridge traffic loading considered only a queue of standstill vehicles. In this paper, a micro-simulation tool is used for generating congested traffic on a two-lane same-way roadway. The total load is computed for a sample long-span bridge. Different congestion patterns are found and they are studied in relation to their effect on loading. It is found that very slow-moving traffic returns the highest loading events, rather than full stop conditions. The topic is especially relevant to existing bridges, where small differences in the loading may play an important role in the safety assessment and subsequent maintenance plans.