Modelli di stima delle emissioni sonore prodotte in ambito urbano da veicoli di trasporto collettivo

In urban areas, traffic represents one of the major pollution factors, but within the traffic flows heavy vehicles and buses are the greatest sources of pollution. These types of vehicles generate similar noise levels, but, as far as strategies for the reduction of noise pollution are concerned, there is a fundamental difference. We can intervene on the circulation of heavy vehicles especially in town centres by limiting and regulating it. On the contrary, buses must function in town centres; indeed, they are often the only means of transport allowed to circulate in limited traffic zones. Vehicles for rail transport (trains, trams) represent one of the major causes of urban noise pollution as they produce high noise levels. This note presents the results of a paper on the formulation of models that, using SEL (Single Event Level) as a noise descriptor, may be suitable for evaluating the noise produced by the circulation of single public transport vehicles on road and rail in urban areas. The models may also be used to calculate the equivalent noise levels connected to vehicle flow (rail and road) at hour or day time intervals. The work consists of three parts. The first part describes certain model expressions derived from specialist literature highlighting the quantities that occur in the description of the noise phenomenon considered. The second part illustrates the procedure followed in the construction of the proposed models, with a calibration based on data collected by means of a specific field survey. The final part reports the results of a comparative analysis between proposed models and models in literature as well as certain applications referring to projects.