Impact of network density on optimizing budget allocation to bridges for improving the resilience of the transportation network

So far, several studies have been conducted to prioritize the allocation of resources to bridges to improve the resilience of transportation networks. Many of these studies have examined the identification of important bridges in a fixed network without changing the topology. But in many networks, there is a possibility of structural change and development in the future that will lead to changes in network density and topology. This changes the importance of the bridges relative to the basic conditions in the decision to allocate the resource. Also, identifying bridges that are smoothly prioritized regardless of future network changes will help to make optimal decisions in the face of resource constraints. In this paper, an indicator called the cumulative importance of bridges is presented, which determines the optimal portfolio by considering the changes in the importance of bridges in different periods of development. A numerical example is provided to illustrate how to use this index. The results of this example show that the use of the index causes the selection of bridges to be different from the optimal selected portfolio with conventional approaches.