Abstract
This study aimed at finding appropriate interval of ranged speed hump from the viewpoint of noise and vibration as well as effect of speed reduction through two experimental installation. In the experiment, "sinusoidal mobile humps" were used. In the first experiment, conducted in Kokubunji city, it was found that 60m-inerval can reduce speed less than 30km/h in all over the road section. However, residents complained the noise caused by re-acceleration. In the second experiment conducted in Bunkyo-ward, Tokyo, the intervals between humps reduced to 20m to make drivers to "give up" to re-accelerate. Judging from the result of questionnaire survey and noise observation, it was successful. (Author/publisher)