Model Calculations With a Fast Field Programme and Comparison With Selected Procedures to Calculate Road Traffic Noise Propagation Under Defined Meteorological Conditions

National guidelines for calculating noise propagation are still in use though progress was made to develop a unified scheme for sound propagation outdoors by taking more physical parameters of the propagation path into account. Besides comprehensive models simpler and faster calculations are under development in order to be used as an engineering model. Widespread classical engineering models from different European countries are compared in this study with physical wave propagation from a defined line source representing traffic noise. The numerical model is based on a fast-field programme. This scheme allows for a very fast calculation of wave propagation in a layered medium including complex boundary conditions. Source properties are carefully adjusted for comparison and the respective meteorological conditions of national guidelines are taken into account. It turns out that the different guidelines are in good agreement with exact calculations up to distances about 1000 m. The socalled downwind condition gives an excellent estimate for the conditions most favourable for sound propagation. The fast numerical calculation scheme enables easy systematic variation of e.g. source properties, meteorological conditions and ground impedances for any sensitivity analysis.JRC.DDG.I.2-Chemical assessment and testin