An urban noise inquiry on the population of the city of Turin using a methodology to define standard sites for the epidemiology surveys

The analysis of the noise impact caused by traffic on the population is a part of a large research program regarding a methodology focused to define standard sites in which to make traffic and noise measurements and to study the impact on the population. A survey has been carried out in some urban roads of the city of Turin, where two main noise sources are present: vehicular traffic and trams. The objectives were to evaluate the perceived disturb by the population in function of some parameters of the monitored sites (i.e. noise, traffic, geometric conditions, surrounding environment, etc.). Some operating phases have been defined to carry out the pilot survey. So, the sites were selected in term of the noise sources and the site characteristics; then the traffic and noise measures were made and a questionnaire was submitted to a sample of the population living in the chosen sites. The results of the survey confirm the importance of the characteristics of the site for the noise level while the perception of annoyance is less related to them. The traffic is not the main variable, but the width of the road, the presence of trees and the tramways are element that mainly influence people disturbance. So, people living in buildings lining roads with tramway line and more than 3000 vehicles per hour perceive a similar disturb of the people living in roads with tramway line and 600-800 vehicle per hours characterised by canyon sections.