Noise Emission at Tunnels
In Germany, presently, the evaluation of the acoustic efficiency of secondary noise control systems is carried out on the basis of the RLS 90. Within this prediction model, the sound propagation in the vicinity of screens, mounds and other general sound reflecting and sound diffracting obstacles can be described by engineering formulas with sufficient accuracy.
However, at the present time, the German prediction model does not include generalized engineering formulas to evaluate specific obstacle geometries like tunnels. The development of such an engineering formula was focus of a research project on behalf of the Federal Highway Research Institute of Germany (BASt).