A methodology for calculating congested traffic characteristic loading on long-span bridges using site-specific data

A probabilistic methodology is developed for the evaluation of characteristic maximum traffic load on long-span bridges for which congestion is the governing condition. It considers all the congestion types that can occur such as stop-and-go waves and oscillating congested traffic. The approach uses site-specific traffic data, such as flow and incident data. Statistics on driver behaviour and traffic incident frequency are assembled from the literature. As an example application of the method, a calibrated traffic microsimulation model is used to obtain the input data for the proposed methodology. The results counter many of the prevailing assumptions for long-span bridge loading.