Rural areas comparison analysis for bridge abolishing and proposal of bridge abolition effectiveness using unsupervised machine learning

Abstract

The aging of bridges, coupled with the shrinking of public financial resources due to population decline, has increased the maintenance and management burden on municipalities. On the other hand, with the expected decrease in traffic demand for certain bridges as a result of population decline, it has become necessary to formulate bridge abolition plans that are tailored to the characteristics of each municipalities. Therefore, this study conducted a case study on 81 municipalities across four prefectures in the Hokuriku region, attempting to categorize municipalities based on their bridge maintenance status to support the formulation of abolition plans using quantitative indicators and to establish cooperative frameworks among similar municipalities. Furthermore, this study proposes the concept of the “Bridge Abolition Effectiveness” as a quantitative indicator to demonstrate the effectiveness of bridge abolition. Through analysis using open data, distinct characteristics of the bridge maintenance conditions were revealed for the categorized groups of municipalities. Additionally, by applying the Bridge Abolition Effectiveness, it was possible to identify municipalities that may be suitable candidates for considering bridge abolition.