The fractal structure of Seoul's public transportation system

We present a fractal study of the public transportation system of Seoul, composed of subway and railway lines. The fractal dimension of the whole network is determined for several years, indicating an increase of D, which is the actual fractal dimension of the lines, from 1.15-1.35. We also determined the actual dimension of the ensemble of the stations (1.50). We discuss the significance of the fact that the fractal dimension of the stations is larger than that of the lines and conclude that it could be a measure of the quality of the system. Our results are compared with those concerning Paris, for which the two fractal dimensions have also been determined. (C) 2002 Published by Elsevier Science Ltd.