Effect of input data in the impact studies of road traffic noise in a time-domain model

The design of efficient screens for preventing noise exposure close to road lanes with high traffic flow is both a technical and an economical stake. This design (including material properties) is usually carried out upstream to in-situ realizations through numerical predictions. However, the uncertainties concerning the input data can lead to strong discrepancies in SPL predictions that are not considered in such impact studies. For instance, the modelling of the road traffic flow stands for a key point. Likewise, the surfaces properties (ground, screens materials, etc.) and the atmospheric conditions (inside and outside the urban canopy) can affect the sound propagation at relatively short distance when considering urban areas. Those scientific topics are currently under consideration in the framework of a french national project called EUREQUA. Thus, the present work treats about this project results by focussing on the effect of such input data in a time-domain model based on the transmission line matrix method.