In the modern world, noise pollution continues to be a major problem that impairs people’s health, and road traffic is a primary contributor to noise emissions. This article describes an environmental impact study of the noise generated by the reconstruction of an urban section of a highway. Noise maps were calculated, and an environmental impact matrix was generated to determine the environmental impact of this reconstruction. The implementation of noise barriers was simulated based on these noise maps, and the effectiveness of the barriers was evaluated using Artificial Neural Networks (ANNs) combined with Design of Experiments (DoE). A functional variable significance analysis was then made for two parameters, namely, the coefficient of absorption of the barrier material and the barrier height. The aim was to determine the influence of these parameters on sound attenuation and on the formation of acoustic shadows. The results obtained from the ANNs and DoE were consistent in demonstrating that the absorption coefficient strongly influences the noise attenuation provided by noise barriers, while barrier height is correlated with the formation of larger areas of acoustic shadow. The environmental impact matrix also indicates that the existence of noise pollution has a negative effect on the environment, but that this impact can be reversed or minimized. The application of simulated noise barriers demonstrated that noise levels can be reduced to legally acceptable levels.

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In this study, noise pollution assessments were performed along Marechal Deodoro Avenue and Batel Avenue, which are two major thoroughfares in the city of Curitiba, Brazil. Eleven points were evaluated at Batel Avenue and 16 points at Marechal Deodoro Avenue. The results of the noise level measurements and the calculation of noise maps indicated that both thoroughfares are acoustically polluted. The simulated and measured noise levels, in the 27 evaluated points, exceed the limits established by law 10,625 of the city of Curitiba, which establishes acceptable levels for the comfort of the population in the external environment. With regard to the traffic composition in the areas under study, the vehicle flow was found to consist mostly of light vehicles, representing 88% of the total flow along Batel Avenue and 85% on Marshal Deodoro Street. Based on the noise maps and measured noise levels, it was found that the entire length of Marshal Deodoro Avenue and Batel Avenue are strongly affected by street noise, which is readily explained by the constant traffic, high vehicle flow (number of vehicles/hour) and high vehicle speed at some points of these thoroughfares.

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This paper discusses a specific source of noise, which is generated by household waste collection trucks. Two areas in the city of Curitiba were chosen for evaluation, one of them a densely populated residential neighborhood and the other in downtown Curitiba. A noise map was created for each area. The evaluation, which was carried out in the daytime in the residential area and at night in the downtown area, revealed noise levels exceeding the limits established by Curitiba Municipal Law No. 10625. The regular use of utility vehicles that generate high noise levels, such as garbage trucks, during nighttime hours in residential areas is thus not sustainable from the standpoint of noise protection laws. Nighttime hours in Curitiba are 10[Formula: see text]pm to 7[Formula: see text]am, but nighttime garbage collection begins at 7[Formula: see text]pm and goes on until 4[Formula: see text]am. Therefore, changes in this schedule are advisable, given the noise impact caused by garbage collection trucks.

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