Supply and Demand System Approach to Development of Bridge Management Strategies

A supply and demand system approach is presented to deal with the inability of existing bridge management systems to determine optimal management strategies when multiple bridges may be adversely affected simultaneously. The supply and demand system approach alleviates this limitation because the optimization problem is formulated to minimize overall costs on the transportation network. The optimization problem is formulated focusing on the ability of the transportation network as a whole (system) to provide an adequate level of service, taking into consideration the role and performance of the bridges in the network (supply) and the consequences if an adequate level of service is not provided (demand). The supply and demand system approach is illustrated by determining the optimal management strategies for five bridges in a real transportation network subjected to two hazard scenarios: overloading due to traffic and scouring due to flooding. The main conclusion is that the supply and demand system approach is a rational approach to the development of optimal management strategies when bridges are adversely affected and may become nonoperational simultaneously.