Min-Max is a decision rule used in decision theory, game theory, statistics and for minimizing the possible loss for a worst case (maximum loss) scenario.

The presence or absence of one-way street will affect on accessibilities of places. In this article, we will adopt this index to every intersections in Kyoto, assuming many situations including cancellation of restrictions of one-way street. Index of “min-max” is very important when we have to decide a location of emergence vehicle station, because this index means that how efficiently we can relief a person in disadvantage.

The left side of figure3 shows distribution of one-way streets in Kyoto (red represents one-way, blue represents two-way streets), middle of figure3 shows closeness centrality of street network under the situation of a normal, and right side shows the same index (closeness centrality) under the situation of cancellation of one-way restriction.

(c) OpenStreetMap contributors, CC-BY-SA

In this figure, we can realize that distances between many places expand because of one-way restrictions (you can see more red circles in right of fig.3 rather than middle of fig.3), and the number of intersections with high score is limited (there is a few red circle). On the other hand, high scored intersections distribute in the center part of Kyoto when cancelling one-way restriction.

Top 100 highest scored intersections in Kyoto.

(c) OpenStreetMap contributors, CC-BY-SA