Verkehrsgeräusche beim Fahren im Gelände/Traffic noise from Off-roading

Off-roading, for example driving on forest or rural roads, on offroad parks or military training grounds, are often facility-related noise that must considered when assessing noise exposure according to TA Lärm. The RLS-19, which is to be used for the prediction of traffic noise on the public transport network, cannot simply be applied to off-road driving. There are several reasons for this. The RLS-19 uses only one source, which becomes "louder" with increasing speed. For Off-roading, this is the other way around, because the drive noise from engine and exhauster dominates the emission level; hence, the levels of a vehicle pass-by decreases with increasing speed. The source of the RLS-19 has no directionality. In heavy military vehicles, however, the exhaust noise is highly directed, for a tank for example, the difference between the source strength to the front and to the rear reaches 11 dB under full load. And for sure, more vehicle classes and more road conditions must be introduced to consider tracked vehicles and to describe the ground, respectively. The article presents the model "ProMoBw-Verkehr". It introduces source separation in rolling and engine noise, and it considers the directivity of the engine noise. Like RLS-19, the DIN ISO 9613-2 scheme is used as propagation model, but with parameters which depend on the vehicle class. Nevertheless, ProMoBw-Verkehr is closely oriented towards the RLS-19 and provides results for the native scope of the RLS-19 that deviate less than + 0,5 dB.