Changes in Transportation Spaces by Car in the Chugoku and Shikoku Regions in Terms of Time- and Cost-Distances

The development of transportation changes the cost space (a map drawn on the basis of traveling cost) as well as the time space (a map drawn on the basis of traveling time). Therefore it is neces-sary to consider changes in both when we study the impact of transportation developments. Review-ing previous geographical studies on this subject, however, few treated time- and cost-spaces at the same time.<br> In this paper, we describe the changes in time-and cost-space configurations in the Chugoku and Shi-koku regions with the development of transportation using multidimensional scaling analysis (MDS).<br> The results are summarized as follows:<br> 1. The time-space configuration of the Chugoku and Shikoku regions has shrunk by 40% since 1970 with the construction of the Honshu-Shikoku Bridge and expressways in this region. The construc-tion of the Chugoku Expressway, among other things, has made a great contribution to the shrink-age of the time-space of the Chugoku region in the east and west directions. On the other hand, the construction of the Honshu-Shikoku Bridge, although called “the project of the century, ” has resulted in limited changes in the time-space configuration, which have occurred only in the region near the bridge.<br> 2. The cost-space configuration of the Chugoku and Shikoku regions shrunk by less than 10% during the same period because a great part of the time reduction, gained by the completion of the Honshu-Shikoku Bridge and expressways in this region, has been offset by their fares. This does not necessar-ily mean that their construction has not improved the transportation conditions in this region, but the addition of new routes, which are faster than the former ones, without any additional payment must enhance the opportunity of the region for choosing alternative routes.<br> 3. The Seto Inland Sea functions in both time-and cost-spaces as a major friction of distance in travel-ing between the Chugoku and Shikoku regions, and that friction is greater in cost-space than in time-space.<br> 4. The INDSCAL method has been used to reproduce the common space in order to observe systemati-cally the changes in time-and cost-spaces brought about by the development of transportation. As a result, the changes in both spaces could be successfully represented in the common space. This means that these changes can be represented by the expansion and contraction of two dimensions of the common space.<br> 5. Our conclusion is that the development of transportation in a region may cause great differences between the changes in time-and cost-spaces of the region. Therefore cost-space and time-space should be taken into account simultaneously in order to understand the changes in transportation conditions caused by the development of transportation.