Social Impact Assessment of Bridges Based on Detour Simulation Using Virtual Person Trip Data

This paper proposes a methodology for assessing the potential social impact of bridge closures using privacy-protected virtual person trip data. The increases in travel distance and time and CO₂ emissions due to detours of individual agents are calculated by performing a path search for each trip using the Dijkstra algorithm on the road network modeled with graph theory assuming the closure of the analyzed bridges. The potential social impact of bridges is quantified as the economic loss estimated based on the increases in travel distance and time and CO₂ emissions. As an illustrative example, the potential social impacts of the bridges located in the Tohoku region of Japan are evaluated. The estimation results demonstrate that even bridges with relatively low traffic volume can cause significant economic loss when closed to traffic. The proposed methodology contributes to the prioritization of bridge management strategies.