Noise Mapping as a Tool to Assess the Noise Generated in the Past, in the Present and in the Future of a Large Latin American City

This work aimed to study the environmental sound impact caused by road traffic noise on several roads in the Northwest part of the City of Curitiba, through in situ measurements and sound mapping. For that, the following steps were carried out: 1) definition of the locations to be evaluated, 2) collection of field data; 3) tabulation of the collected data; 4) acoustic mapping; 5) evaluation of past, present and future scenarios; and 6) conclusive assessment. The object of this study is the assessment of environmental noise on roads of great importance for the movement of vehicles from one end of the city to the other. The roads run through five large commercial and residential districts with a large flow of vehicles and people. To characterize the noise pollution in the stretches evaluated, 22 measurements were made in different locations. Sound measurements were performed according to the recommendations of the NBR 10151/2000 standard. The Predictor 8.11 sound analysis software was used to make the acoustic maps. A reference scenario that represents the current “acoustic panorama” was evaluated. Three hypothetical and distinct scenarios were also created to assess noise in the chosen areas. In scenario 1, the hypothesis was created that the number of vehicles is reduced by 50% compared to the current one. In scenario 2, the hypothesis was created that the number of vehicles is reduced by 75% compared to the current one. Scenario 3 simulates noise in sensitive areas considering the time span of 20 years, that is, with the increase in the number of vehicles by 100%. The results suggest that the acoustic situation of these stretches characterizes the existence of environmental noise pollution. The scenario with a 50% reduction in the number of vehicles and reveals that the measures adopted were not sufficient to significantly reduce sound levels. The scenario with a 75% reduction in vehicle flow shows that the measure adopted would be significant to reduce sound levels within the limits established by legislation. And in the future scenario it is possible to show that the flow will be extremely saturated 20 years from now, that there will be asignificant increase in sound levels, and consequently an increase in environmental noise pollution. In this way, it is evident that just one control measure taken is not enough to solve this problem. It is necessary to create a medium and long term plan, with several measures that work together to combat noise efficiently.