Monitoring of urban road traffic noise monitoring with a model based sensor network

The constant growth of road traffic leads to increasing noise problems in urban areas. They especially become visible as ‘hot spots’ on noise maps, which have to be made by European cities. To solve these problems, a large variety of measures can be applied, varying from silent roads and noise barriers to reduced speed limits. Recently TNO has been developing a new method to assess the effectiveness of these measures in detail. The method is based on an automated local sensor network that consists of different types of sensors. Each passing, individual vehicle is being traced with microphones, video, radar and a license plate recognition tool for a certain period, resulting in a (large) database. The results of these measurements are combined with a numerical noise emission and propagation model to analyze the possibilities and the effect of acoustic measures. Both measurement and model results can be visualized in a software tool, in which also different cross-sections of the database can be shown. With the measurement information and the model also the contribution of different vehicle categories to the average sound level (LDEN) can be determined, which allows measurements on a more detailed and more effective level. In this article a number of analyses with this method will be shown for a test case on an urban road in the Dutch city of Delft