There are various issues need to be addressed when drawing estimated road traffic noise maps in Japan. One of them is there is a trade-off between computational load and estimation accuracy due to the number of sound receiver points on the building facades where the noise exposure is evaluated. An interpolation to generate receiver points on facades as post-processing of a computation made on relatively coarse receiver points can be a solution to achieve compromise between computational load and estimation accuracy.
In this study, estimated noise maps are drawn in nine real city blocks in Japan with different land-use areas by placing sound receiving points with intervals of 1m, 5m and 10m. The map of the 1m interval is used as the reference noise levels. The maps of the 5m and 10m intervals are interpolated to the 1m interval using 29 interpolation methods.
The optimal combination of the interval of sound receiving points and the interpolation method are found based on error of the interpolated maps compared to the reference map.