EXAMINATION OF ROAD NETWORK EVALUATION METHOD USING MATRIX TREE THEOREM

Abstract

Since natural disasters such as large-scale earthquakes and heavy rains occur frequently in Japan, road connectivity in an emergency is extremely important. In this research, we propose a method for calculating links with weak connections in the emergency transportation road network in Ishikawa Prefecture using the matrix tree theorem. In this research, the reduction rate of the spanning tree of the network is adopted as a new index for vulnerability evaluation. In this index, the number of spanning trees in the network is calculated using the Laplacian matrix, and the amount of decrease in the number of spanning trees in the network when each link is disconnected is used. The characteristics of this index are low calculation cost, high robustness to network expansion, and no OD setting. We will analyze this proposed method for the emergency transportation road network in Ishikawa Prefecture and examine the validity of the method.