Traffic Noise Prediction with Nord2000 - An Update

摘要

A comprehensive method for mapping traffic noise levels is an indispensable tool for road administrations in their effort to mitigate traffic noise. Nord2000 is a new generation prediction method for environmental noise. Predictions can now be made of third-octave band levels of road traffic noise propagating over complex terrain under almost any weather condition. This allows accurate computation of yearly average noise levels as required by the European directive on environmental noise. The Danish Environmental Protection Agency in 2007 decided that computation of surface transportation noise shall be carried out using Nord2000. At the same time the yearly average L_(den) was introduced as the Danish noise measure to characterize population exposure to transportation noise. Computations are made by commercially available software, and test cases have been defined as a measure to prove software compliance. For rough estimates freeware is provided for looking-up pre-calculated noise levels in typical cases. Road surface conditions are taken into account by correcting default values for the pavement lifetime average condition. Noise barriers now seem to come out slightly less effective than before, when noise levels were predicted for conditions of a slight downwind perpendicular to the road.