2001 年 66 巻 549 号 p. 231-237
The purpose of this study is to construct a fundamental evaluation theory for the various functions of a road network in district scale from the city scale viewpoint. This theory is based on Percolation Theory because of some similarities between road blockade by houses collapse and the site process percolation model of Square lattice. The distinction of this theory is that the function of road network after an earthquake will be evaluated for any size district, if average probability of road blockade and road shortage in a district is given. In this paper, we explain the constructing process of this theory in detail and indicate an evaluation method of the road network function focusing on the fire fighting difficulty.