A model based monitoring system is applied on a local scale in an urban area to obtain a better understanding of the traffic noise situation. The system consists of a scalable sensor network and an engineering model. A better understanding is needed to take appropriate and cost efficient measures, especially when changes to the local infrastructure are proposed. The monitoring system provides information about the sound level distribution in the area in time and place. This can be used to create dynamic noise maps or to characterize the soundscape in the area. Results of a field test of two weeks in an urban area of 400 by 200 meters are used. Three different areas are considered: 1) the main road which is the major source for traffic noise, 2) a quiet street, and 3) a quiet courtyard. The noise level measurements near the main road are compared with the engineering model results. Next, with the use of actual source levels from the measurements, the sound levels in the quiet street and the quiet courtyard are calculated. By comparing the model results with measurements in these areas the parameters in the model are updated to better reflect the actual situation. © 2013 Acoustical Society of America.