Changes in the Spatial Patterns of Motor Vehicle Freight Flows in Japan

Freight flows reflect the economic and transport systems through demand-supply activities In the past, a limited number of studies of freight flows dealt with dynamics analysis, The dynamics analysis of freight flows can show the spatial reorganization induced by economic growth and transportation development through freight flows over time.<br>The aims of this paper are (a) to clarify changes in the patterns of freight flows, (b) to clarify the relationship between volume of shipments and interprefecture flows and economic activities. in each prefecture and (c) to show the spatial reorganization due to changes in the transport system through motor vehicle freight flows between 1965 and 1977 in Japan. During this period, there was rapid economic growth and changes in the transport system. The most noticeable change was the rapid decline in rail's share (ton or ton-km) and the rise in motor vehicle freight's share of traffic, accompanying the construction of expressways and the improvement of roads.<br>Data for this study comes from the interprefectural origin and destination survey (46×46) which was conducted by the Ministry of Transportation in 1965 and 1977. Freight measured in this study are agriculture and fisheries products, metal and machinery products, and light industrial products, in interprefectural flows. These freight were selected by the volume of each freight category for total flows and by changes in the rates of freight flows in each freight category in 1977 in comparison with 1965. Agriculture and fisheries products is a typical freight category which shows a little volumes for total flow in interprefectural flows and which shows a low rate of increase. Metal and machinery products is a typical freight category which shows a high volumes of total interprefectural flow and a high rate of increase. Light industrial products is a medium-type freight category.<br>Major flows of over 0.3% in proportion to total flow in motor vehicle freight flows were analyzed. The relation between the volumes of shipping (arriving) and employed persons by industries were analyzed by step-wise regression analysis. Then, the changes of total freight flows were compared with the changes of prevailing industries which were measured by a modification of Weaver's method of combination analysis in each prefecture. Changes in agriculture and fisheries products, metal and machinery products, and light industrial products flows are compared with the rates of change which were measured by the changes in products of their freight in each prefecture.<br>The results are as follows:<br>(1) The volumes of shipping (arriving) are related to the development level of ‘other manufacturing’. Major flows appear between Tokyo, Osaka, Aichi and regional-center prefectures (Hiroshima and Fukuoka) and their surrounding prefectures in 1965. In 1977 the rates of major flow relatively decreased between Tokyo, Osaka and Aichi and surrounding prefectures and increased between prefectures of the northern Kanto region and a regional-center prefecture (Miyagi). Therefore, the focus of motor vehicle freight flows on the larger city and regional-center prefectures did not change but there were changes in spatial patterns of freight flows (Fig. 1). The reasons for the change are (a) the formation of special production districts, (b) the reinforcement of the role of the central wholesale market in regional-center prefectures and (c) the acceleration of motor vehicle freight flows of material and products of machinery manufacturing with the new location of machinery manufacturing in the northern Kanto region.<br>(2) Major flows of agriculture and fisheries products are apparent between Tokyo and its surrounding prefectures in 1965 but appear among Tokyo, Osaka, Aichi, regional-center prefectures (Miyagi and Fukuoka), and their surrounding prefectures and special production districts, in 1977.