sonROAD18 is a road traffic noise emission model developed on behalf of the Federal Office for the Environment (FOEN). It is based on the formalism of the European model CNOSSOS, but uses the SWISS10 vehicle categories and thus represents the current vehicle fleet in Switzerland. In addition, emission values for buses and trams as well as agricultural vehicles are available. The emissions of an individual vehicle are characterised by means of the radiated sound power in one-third octave band resolution and as an A-weighted sum level. In addition, a directivity term accounts for the decrease in emission strength towards high elevation angles. In contrast to the previously used model StL-86+, sonROAD18 also covers the low speed range and allows predictions down to 20 km/h. The figure shows as an example the speed dependency of the sound power level for four vehicle categories. Besides total noise, the two components propulsion and rolling noise are shown.

Involved in the project:

Contracting authority:
Contracting authority: FOEN, Urs Walker, Noise and NIR Division
Project leader: Michael Gerber, Noise and NIR Division

Project team Empa:
Kurt Heutschi, Barbara Locher, Katja Henz

In the project integrated external contractors:
Grolimund + Partner AG, 3006 Bern
B+S AG, 3000 Bern 15

Data providers:
Projekt MFM-U, ASTRA, TCS, Kanton Aargau, Kanton Graubünden, Kanton St. Gallen, Stadt Zürich, B+S AG, Basler & Hofmann AG, Grolimund + Partner AG, IFEC ingegneria SA