Calculating and assessing road traffic noise

Road traffic is one of the most important sources of noise in urban areas. Its emission may be reduced by improvements of engines, tyres and road surfaces, but this will not eliminate the problem completely in the foreseeable future. It is therefore important to evaluate this noise thoroughly when alternative strategies are discussed in city planning projects. An important step in the evaluation process is the calculation of noise maps for urban areas. The procedure is demonstrated without algorithms and formulas, because these depend on the national standards and other regulations. The calculations take into account topographic features and screening and reflection by objects like buildings and other barriers near source or receiver. With the noise maps (or the corresponding data files) the alternatives can easily be ranked in order of noise impact. The calculation is demonstrated with a simple example. All the figures, calculations and maps were produced using Datakustik's Cadna/A software.