Abstract
In order to investigate the effects of high speed train noise, we made a social survey of the community response along the New Tokaido Line and the New Sanyo Line in July of 1972. Though the number of samples were only 424, data showed little internal inconsistency and reasonable results were obtained. The New Tokaido Line was opened to traffic in September of 1964, covering 515 kilometers'distance between Tokyo and Osaka in three hours and ten minutes at the maximum speed of 210 km/hr. The New Sanyo Line in turn was opened to traffic in March of 1972, covering 161 kilometers'distance between Osaka and Okayama in an hour at the maximum speed of 210 km/hr. More than half of the railroad tracks in the New Tokaido Line is constructed on a banking roadbed, while most part of the New Sanyo Line is an overhead railroad built in concrete. In these lines, a train runs in few varieties of formation, at the speed prescribed to every fixed location. Variation of the train noise levels, therefore, is within a few decibels at a given location. The survey was carried as that of informant's life environment, and the questionnaire included 14 items about attitudes to neighborhood, 17 items about reactions to train noise, 5 items about attitudes to noise in general and others. Relations between Likert scales describing direct effects of train noise on the community and peak levels of train noise were obtained;also peak levels corresponding to the neutral point of each disturbance scale were read out(for example, see Fig. 2). In addition, relations between proportions of positive response to disturbance scales and peak levels of train noise were obtained(for example, see Fig. 3). Peak levels corresponding to neutral points and some proportions of positive response are listed in Table 2. Our survey includes"house vibration"(Fig. 4)and"TV picture flicker"(Fig. 5)also. Difference of community responses between New Tokaido Line and New Sanyo Line seems due not only to the difference of habituation but also to the difference of attitudes to noise in general. Train noise corresponding to the same community response is about 10dB higher at the New Tokaido Line than at the New Sanyo Line in WECPNL. Comparing community response to train noise with that to aircraft noise in NNI, values in Table 4 were obtained. Table 5 shows the estimated community response through NRN and observed response in our survey. A percentage of informants who stated high disturbance under lower noise level(about 70dB(A) or less) and percentage of informants who stated low disturbance under higher noise level (about 80dB(A) or more)were both 10 percent or less(Table 6). The former is the percentage of informants who rated the train noise as category 4(such as"I am frequently disturbed")or category 5(such as"I am very frequently disturbed")under the exposure to noise levels below that corresponding to category 2(such as"I am little disturbed")on the Likert scales;the latter is the percentage of informants who rated the train noise as category 2 or category 1(such as"I am not disturbed at all")under the exposure to noise levels above the level corresponding to category 4 on the Likert scale.
