The Tramsforrnatien of Aeeessibility Spaces in terrrms of Public Transport in Iwate Prefeeture

This study aimed to examine accessibility spaces and their transformationin Iwate Prefecture through the analysis of public transport in 1974, 1980, and 1985. The year of 1974 was a year after the first oil crisis, while the year of 1980 was a year after the second oil crisis. Tlae year of 1985 was three years after the establishment of the Tohoku Sinkansen Line. Through the comparison of traffic phenomena of these three years, this study clarified the reorganization of the bus and railroad network caused by soeio-economic changes. It also denaonstrated the changes in relationships between every pair of zones due to the reorganization. The accessibility data in this study recorded the number of possible trips between every pair of zones in a clay by the bus and railroad network. This data contained the information about transfers. First of all, the standardized accessibility scores (S.A.scores) were calculated in order to measure the convenience of public transportation in each zone. Five results were drawn from the analysis (Figs. 6 and 7). (1) Zones along the Tohoku Line south of Morioka City had high S.A. scores in any year. (2) Zones in the northern part of this prefecture did not have high S.A.scores. (3) There was a big gap between the sotuthern area and the northern area. Although this gap was narrowed a little in 1985, the southern area still had higher S.A.scores than the northern area. (4) Zones in the coastal area continually declined its relative position in terms of S.A.scores from 1974. In other words, a gap between the coastal and the inland area expanded. Second, the accessibility spaces were investigated in each year in order to clarify the factors of the change in the accessibility in each area. Quasi three mode factor analysis is conducted to find the accessibility spaces (Fig. 5). As a result of factor analysis on origins based upon Equations 6 to 12, eight factors are derived. Distributions of the origin factor scores show Fig.8. Next, as a result of destinated areas based upon Equations 13 to 16, eight factor are devided. Fig. 9 shows distributions of the destination factor loadings. Fig. 10 shows the accessibility spaces of any years based upon the core matrix calculated by Equations 17 to 19. The first origin factor and first destination factor indicated the accessibility space composed of Morioka City and its surrounding zones. The second origin factor and second destination factor indicated the aceessibility space along the Tohoku Line in the south of Kitakami. The third origin factor and third destination factor indicated the accessibbility space composed of the Ninohe City and its surrounding zones. The forth origin factor and forth destination factor indicated the accessibility space along the Hachinohe Line. The fifth origin factor and fifth destination factor indicated the accessibility space along Kita-rias Line. The sixth origin factor and sixth destination factor indicated the accessibility space along Minami-rias Line. The seventh origin factor and seventh destination factor indicated the accessibility space along Kamaishi Line. The eighth origin factor and eighth destination factor indicated the accessibility space along Ofunato Line. Any accessibility spaces formed along railroads. The results of analysis of the core matrix (Table 1) based upon Equations 20 and 21 indicated that the accessibility spaces along Tohoku Line increased their accessibility, but that the accessibility spaces in the coastal area decreased their accessibility. These results indicated that the zones along the Tohoku Line exalted its position in convenience of public transport after the oil crisis. The position of Morioka City and its surrounding zones exalted more prominent, especially afterthe opening of the Tohoku Shinkansen Line. It was also demonstrated that the gap between the inland and the coastal area was expanded.