道路周辺環境の総合評価手法に関する一研究

筑波研究学園都市における事例研究

抄録

For making plans of preventing the road traffic pollution, it is required to evaluate the current state of the environment from the viewpoint of residents. The study aims to construct a comprehensive evaluation method to cope with this requirement.
The method utilizes the framework of systems analysis. The total value for the comprehensive evaluation, V₀, is estimated (V₀ denotes the estimated value) by the following equation of linear combinational form,
_??=_??_W_iV_i
where, V_i and W_i denote the evaluation values and the relative weight of individual item i of environmental quality, respectively. The major characteristic of the method is in utilizing the following two techniques to measure the residential consciousness and opinions about their environment. First, we estimate a value of the residents for each item, V_i, by conducting group surveys. Second, we estimate a relative weight for each item, W_i, by employing computer-aided Delphi conferences, utilizing the Group Analyzer System of the NIES, which is a computer-aided voting system. The uniqueness of the method lies in its approach of measuring residential consciousness and opinions not by usual questionaire sheet surveys but by citizen participated conferences.
This method was examined by conducting a case study at road side area of Tsukuba Science City in late 1979. The study area is located in the central residential district of Tsukuba Science City. From this district two housing blocks were chosen for the comparison of the road side environments. One block faces a main road, Higashi-odori Boulevard (block 1), and the other is about two hundred meters from the boulevard (block 2). Each block is about four and a half hectares in areas. We selected not only such physical items as exhaust gas or noise by car, but also socio-economic items. The selected eleven items are grouped into four categories of safety, health, convenience and comfort. In order to measure the values of V_i and W_i of equation (1), four experimental conferences were held at the NIES. First two conferences were. participated by the housewives of the housing block 1 and 2, respectively. The other two conferences were held by the groups of university students (the University of Tsukuba), which were chosen as reference groups. The number of participants of each conference was 23 to 25.
The major results of this study are summarized as follows.
1) Similarity of the measured values of V_i's of two reference groups was verified by chi-square tests. It is concluded that our procedure is not biased and is suitable to acquire stable values of V_i's from small groups which are sampled from a population.
2) As was expected, on the other hand, the values of V_i's between the residential groups and the reference groups were different. Furthermore, the values of V_i's of the residents of the two housing blocks differed in several items. We concluded that it was impossible to replace V_i's of the residents of particular areas by those of non-residential people.
3) The values of W_i differed according to the housing blocks and reasonably reflects the state of their present living environment.
4) In the computer-aided Delphi conferences for measuring the values of W_i, it took at most two iterations to acquire consistent values of W_i in the cases of the students' groups, and longer iterations for the housewives' groups. The total response time of each conference was found to be short enough for the practical use of this method.