The Intra-urban Automobile Flow Pattern and the Urban Structure in Nagoya

Abstract

Urban transportation functions as a means of dealing with various sorts of demand-supply relations among urban functions or facilities scattered throughout a city. To analyze urban transportation from a spatial point of view, therefore, it is necessary not merely to direct our attention to the flows of goods and persons as such but also to consider them with reference to the arrangement of various urban facilities and to the manner of land use, etc. This paper aims to inquire into what pattern the automobile flow has in Nagoya, one of the representative metropolises in this country, where the automobile transportation bears a comparatively high ratio to the whole urban transportation, and into how the pattern is related to the urban structure.First of all, I have examined the relation between the volume of automobile transportation and the socio-economic features of areas, and the factors in the variation of the volume of automobile transportation from one region to another. The result is that the volume of automobile transportation is greatest in the central area of the city which has a large number of automobiles and brisk economic activity, while it tends to decrease proportionally depending upon the distance from the central area. And the volume varies with the manner of land use. Generally speaking, the volume of transportation concerning commercial, industrial and residential land use is great in every area. Furthermore, in the case of land use for commerce, business and housing, the volume of transportation per square kilometre differs only a little in different areas, while in the case of land use for urban management, transportation, agriculture, etc., there is a considerable difference. On the other hand, the volume of inter-regional transportation is in inverse proportion to the distance between regions and in direct proportion to the amount of economic activity; it is possible to account for this by means of the so-called gravity model.Next, I have applied factor analysis in order to derive the pattern of automobile transportation from 48×48 origin/destination automobile flow matrix, thereby setting up 12 functional areas. The arrangement of these functional areas represents a sectoral feature centering around the city center; this feature is held in common with many other cities. To put it more strictly, however, the sectors do not center around the heart of the city as the sole focus common to them all, but rather they divide the city into blocks each with its own center. This may be a characteristic flow pattern of automobiles in metropolises.On the other hand, it has been proved that the transportation flow pattern bears a close relationship to regional distribution of socio-economic activities within the city, topological features, road networks, etc. In other words, it has been confirmed to some extent that each of the functional areas consists of regions with different land use patterns judged according to the Modified Weaver's Method, and that there is transportation between regions of different land use. And examination of the border lines of the functional areas suggests that rivers, canals, railroads, etc. have a function of obstructing or restricting transportation flow. These may be considered as factors in the formation of the transportation flow pattern peculiar to urban areas.As stated above, transportation and movement within an urban area are closely related to factors in the urban structure such as land use patterns. Consequently, as a problem for the future, it will be necessary to explain this relationship between them from various standpoints and to make a more microscopic analysis of the matter with major emphasis laid upon the individual's behavioral pattern.