Prediction of noise reduction through vehicle path rerouting.
Traffic noise, produced by moving vehicles, is described in terms of the day-night average sound level L(dn) and the day-evening-night level L(den). Both levels depend on the path of noise sources, such as road vehicles or aircraft. Usually, noise source path is rectilinear. Substituting a circle arc of radius R for the straight path segment yields noise reduction DeltaL=DeltaL(dn)=DeltaL(den). Assuming that noise propagation is governed by geometrical spreading, air absorption, and ground effect, relationship between DeltaL and R is derived. For example, replacement of a straight road at the distance of 100 m with the road of radius R=270 m and the angle Phi=68 degrees yields the noise reduction of 4 dB. In the case of road traffic noise, the presented results seem to be a viable alternative to barrier construction.
Makarewicz
Rufin
R
Institute of Acoustics, A. Mickiewicz University, Umultowska 85, 61-614 Poznan, Poland.