Effect of accuracy of digital map data on predicting road traffic noise in Japan

Abstract

Use of GIS for evaluating the Environmental Quality Standards for Noise is established at local authorities in Japan. A digital map on a scale of 1/2,500 is generally used. However, it has not been clarified yet whether the digital map with such a scale has an accuracy to apply for the estimation of environmental noise. A ground plan of buildings on the digital map is a roof plan, because the digital map data are made on a basis of an aerial photograph. It is feared that the noise estimated by using such a map may have some differences in the effects of buildings on the noise propagation from reality. In spite of the fact that the propagation of road traffic noise is highly affected by whether a road is visible from receiving point or not, when the roof plan is used as the floor plan, the road is sometimes visible from the receiving point on the digital map, though it is invisible in practice. The aim of this study is, therefore, to reveal the effect of accuracy of the digital map in GIS on the estimation...