Acoustic screening effect on building façades due to parking lines in urban environments. Effects in noise mapping

- The parking lines in streets may modify significantly the sound field.
- A screening effect associated with the presence of parking lines is observed.
- This effect is not considered in noise maps con ducted under European Directive.
- Results show the importance of this effect in selection of the height for measures.
- This shielding effect may influence the validation of computerized noise maps.

European Directive 2002/49/EC indicates that strategic noise maps are the main tool for assessing the exposure of the population to environmental noise. When these are made through computational methods, the presence of lines of parked vehicles on the sides of urban streets is not usually considered, but recent studies suggest the possibility that its effect on real exposure to noise on buildings façades is not negligible. In this study, the effect of parking lines in urban street design on sound level distribution is numerically studied with the Boundary Element Method (BEM). A screening effect associated with the presence of parking lines is observed. This effect varies depending on the height for measurement and the distances between the sound source, the parked vehicles and the facade of buildings. The results show that the effect can be significant in many urban street configurations in order to determine the exposure to traffic noise of dwellings. As a consequence, by not considering it in noise mapping, the accuracy of the outcomes of noise maps conducted according to European Directive can be influenced.

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