Walkability of the city, which is now one of the central issues on urban planning, is considerably effected by the road connectivity. There are a lot of measures that can be used to determine road connectivity, and each of them has its advantages and disadvantages. In this paper, we propose a new index of road connectivity, travelable road magnification ratio, which is defined as the magnification ratio of the total length of travelable roads within a certain distance from a measure point, to this distance. The relation between travelable road magnification ratio and the travel distance can be displayed on a graph, which illustrates the characteristics of the road connectivity around the measure point, such as openness and closeness. As a case study, we applied this method to the analysis of the road connectivity of Kyoto city.
