Validation study on road traffic noise: assessing various traffic scenarios

TraNQuIL2 is an epidemiological research project, which addresses the relation of acute and long-term health effects from transportation noise and the benefit of different mitigation strategies. Within this project, a small validation study on the exposure modelling for various road traffic noise situations in both rural and urban areas of Switzerland was carried out. The study focuses on evaluating the accuracy of the emission and the sound propagation modelling to nearby buildings and aims at identifying potential exposure misclassifications. Results indicate a tendency of the model to overestimate actual source emissions (mean: +1.5 dB), which might be explained by lower actual travelling speeds or different pavement properties compared to model assumptions. As the sound propagation modelling yielded accurate results, this leads to a corresponding overestimation at exposed facades. However at facades facing away from the street, larger uncertainties in the propagation calculation and a tendency to overestimate the attenuation was observed, highlighting the complex nature of sound propagation in such situations. These findings emphasize the importance of using refined emission and sound propagation models and accurate input data for noise effect studies.