When people visit special protection zones of national parks such as Oze (Ozegahara, Japan), they expect to have the high-quality experience of a visit without the feeling of congestion. This study's goal is to create a specific index to evaluate the sense of congestion that subjects felt while observing people on a wooden path using a rest terrace as a viewing platform. This study evaluated the sense of congestion of approximately 20 subjects who viewed the wooden path from a rest terrace in Ozegahara. In addition, this study also evaluated the sense of congestion of another 71 subjects who looked at photos of the wooden path while located at the same terrace. The results are summarized as follows: Under the conditions that (1) the subjects could view a landscape of 500m, and (2) the subjects watched people walking on the wooden path for more than 7 minutes; the limit of the acceptable number of people on the wooden path was approximately 100. Acceptability was defined by subjects as follows: (A) subjects perceived the density as not too high and (B) subjects managed to feel a sense of satisfaction. The number of people with which the subjects considered the density as low and felt a sense of satisfaction was approximately 20-30.
