Analysis of the Effectiveness of Different Noise Reducing Measures Based on Individual Perception in Germany

Traffic noise is one of the main problems cities have to deal with. Therefore noise reducing measures have been carried out. In order to choose suitable measures it is important to know about their effects. The normal way of evaluating these measures in Germany is to focus on the reduction of sound level. But noise, defined as a sound which is perceived as nuisance cannot be measured just by these numbers. It is an individual perception and therefore varies from person to person. Moreover, depending on the type of measure, there are side effects which have an influence e.g. on accessibility (barriers) or the living environment (green), which in turn affects people's annoyance. Therefore the Ministry for Climate Protection, Environment, Agriculture, Nature Conservation and Consumer Protection of the German State of North Rhine-Westphalia funded a study carried out by the Institute for Urban and Transport Planning. Main part of this study was a survey performed in four German cities where the following five measures had been implemented over the last years: noise reducing asphalt, grass covered tramways, noise barriers, soundproof windows and night driving bans for lorries. The aim of this research was to “measure” the subjective effect of noise reducing measures on residents. The results show that residents feel negatively affected by traffic noise in different ways, e.g. that noise reduces their living quality and causes sleep problems or makes it necessary to keep the windows shut. The main health problems which were reported are nervousness, sleep and hearing problems. The longer residents live close to traffic noise, the higher is the rate of noise induced health problems. After implementation of the measures almost all of the residents experienced an improvement of their living situation. The rate of highly annoyed people was reduced by 8,3% to 22,9%.