Effects of speed limits introduced to curb road noise on the performance of the urban transport system

Abstract

IntroductionAround 113 million of EU citizens are affected by road traffic noise which could be harmful Many authorities attempt to limit traffic speed to reduce traffic noise. The purpose of the research is to assess the impact of speed limits aimed at reducing the negative consequences of road noise on the efficiency of the transport system in a city (Łódź, Poland) which faces severe congestion and road noise. Theoretical backgroundSpeed reduction is primarily employed to improve road safety, which is why there are few studies on the impact of speed reduction on road noise within the transport system. MethodTwo traffic models were built to illustrate the impact of traffic speed restrictions on roads where the code currently permits speeds above 50 km/h and along which noise immission violations are observed. The first is a base model representing the current state, while the second shows urban mobility patterns under the assumption that traffic speed has been curbed. The comparison of the results of the above-mentioned models enables the presentation ex-ante of the external costs of the measures applied to reduce transport noise, on the efficiency of the transport system. ResultsSpeed reductions will not disturb the equilibrium of the urban transport system as a whole, as it is able to cope locally with the resulting disruptions. The proposed of road speed limits on the selected roads would have a marginal impact for the level of congestion. ConclusionsThe applied research methods give a good diagnosis in terms of the research goal set. However, to fully estimate their impact on noise reduction, they should be expanded to include analyzes of noise level reduction along those roads where speed limits may be introduced, and to examine the noise levels on those roads that would become alternative routes for road users.