Kazunori HASHIMOTO

A Research Village Isolated and Road Network Redundancy for the Chuetsu Earthquake

Syoji MATSUMOTO, Kazushi SANO, Satoshi TSUTIYA


At 17:56 on October 23, 2003, the earthquake of magnitude 6.8 occurred in Cyuetsu district of Niigata Prefecture. Landslide on a mountain slope and much traffic blockage occurred and 61 isolated villages occurred.
Even if the shortest route from an origin to a destination is cut off, on alternative function such that an alternative route is replaced with it exists in a road network. This characteristic is usually called as a RI(redundancy index of highway networks between pairs of nodes).
The RI of each village is computed to evaluate the danger of isolation. Next, the importance of each link is evaluated from RI. Finally, the restoration priority of road links is examined simulating an actual disaster situation.