The impact of collapsed vacant houses on the functionality of emergency transportation road networks

Japan frequently experiences earthquakes.In the 2024 Noto Peninsula Earthquake, collapsed houses disrupted emergency transport roads, delaying recovery efforts.This study evaluates the impact of collapsed vacant houses on the emergency transportation roads network.Using data from 12 cities in southern Ibaraki Prefecture, we identified vacant houses that may obstruct traffic.We assessed road passability based on vehicle size.Two optimization problems were analyzed for routes between municipal offices: the minimum spanning tree problem, focusing on minimizing removal costs of vacant houses, and the shortest path problem, emphasizing rapid response.We quantified the tradeoff between cost efficiency and responsiveness to support better disaster planning and resilient transportation network design.