Abstract
The purpose of this paper is to show tour-distance Voronoi diagrams which represent catchment areas of facilities under the assumption that users use more than one facility. Bisectors composing tour-distance Voronoi diagrams are generally curved lines, although those of higher-order Voronoi diagrams are composed of straight lines. It is observed that contiguous facilities have larger joint catchment areas than scattered facilities. Applying them to locational selection of competitive facilities, it is found out that locational concentration tends to be superior for facilities which maximize their catchment areas, if users make tours to move around from one facility to another.
