商業地区のストリートの快適性に関する研究 心理量と物理量を考慮した評価手法の提案

小﨑 美希, 林 鍾衍, 赤司 泰義, 平手 小太郎
日本建築学会環境系論文集, 2017, 82 巻, 738 号, pp. 705-714
https://doi.org/10.3130/aije.82.705

Abstract
Public spaces such as agora or plazas are commonly made to enhance the activity. Yet, in Japan, it is not widely used, which is probably because Japanese tend to gather in a linear way rather than circular way. This research tries to establish the evaluation methodology of the street pleasantness of commercial district of practical use for regional revitalization and improvement of commercial street environment.
 Using previous studies on multiple environmental factors and evaluation structures on outdoor environment, the structure of the evaluation was built. Evaluation sheet consists of three layers, named as follows; axis, factors and grade items. Grade items consists of 5 grades with a certain points. Each axis, factors and grade items has weighted coefficient (respectively, Xn, Yni, Znij) that shows the amplitude of the influence to street pleasantness. The weighted coefficient was derived using the results of evaluation experiment and by analyzing the results using multiple regression analysis. The main point of the weighted coefficient is that it shows the rate of influence to the street pleasantness.
 The evaluation experiment took place at 12 streets selected among near Tokyo station and Ginza area. Streets were selected so that environmental factors and spatial factors that will influence street pleasantness will vary. For example, there were streets with trees planted on the sidewalk and streets without any greenery. The evaluation items were chosen related to each axis, factors and grade items, and were rated using 5 rating scale. The results were analyzed using multiple regression analysis and standard partial regression coefficient was derived. Then it was converted into ratio, which will show the rate of influence.
 The weighted coefficient was verified using other evaluation experiment result done at two streets in Jiyugaoka. The measured street pleasantness and predicted street pleasantness, which was calculated using weighted coefficient and they were compared. The correlation factors were over 0.8, and showed its fitness.
 The grade items and five grades were derived from the previous studies. Reference that shows the relation between psychological rating evaluation and physical environmental measurements were searched. By using its results, five grades were linked with physical measurements. In this study, the physical measurements were limited to environmental factors. Spatial factors and its physical measurements, such as width and length of the streets are yet to be considered.
 The validity of the physical measurement and its grades were tested through the results of the analysis of physical measurements done with the evaluation experiment. Using logistic results, 50% threshold value were derived and compared with the grades from the previous research. About half of the grade items and its grades were shown valid, and the grading can be substituted using physical measurement.
 This study has its point in creating the evaluation chart by combining the results of previous studies. Its validity was shown by the results of evaluation experiment and physical measurements taken at that time. The second point of the evaluation chart is that the weighted coefficient shows the influential rate to the street pleasantness. By this system, not only the street pleasantness can be graded and predicted, but also will show the points that need to be improved. Further analysis on spatial physical factors will provide designing guidance.