抄録
The authors proposed a propagation model for ground effect of vehicle noise. Since it was given by a simple formula and related charts, rough estimation of vehicle noise level at a road side could be made without any precise computation. In this paper, the model is revised for wide application to a prediction procedure of road traffic noise. Numerical expressions are given to the model by introducing a new additional parameter. The parameter, which is simply determined from the heights of a source and a receiver, is found to play an important role in the propagation model to determine the property of vehicle noise over absorptive ground. The revised expressions are applied to outdoor sound propagation on lawn field for A-weighted vehicle noise. Good agreements are obtained between calculated and experimental results. Calculation rules are empirically specified to apply our model to a prediction procedure of road traffic noise. The validity of the procedure is checked by the results of scale model experiments for typical road structures.
