A Study on Probability of Street Blockade at a Large-scale Disaster in a Historic Preservation Area

Most of the Historic Preservation Areas are very vulnerable to disasters. The aim of this study is to build probability of street blockade for evacuation routes planning from each house to an evacuation place at a large-scale disaster in such a historic preservation area. The study area is Hamanaka Machi Happongi Shuku in Kashima city, Saga Prefecture, which has been designated as a preservation district of traditional buildings. To achieve this aim, we referred to the formula for probability of street blockade for normal city area made by Tokyo Fire Agency. We revised it, considering the width of street under 4 m, structure of houses along the street, and the distance from the house to main street with the width over 4 m. Then, we applied the revised formula to the study area.