Assessment and Prediction of Environmental Noise Generated by Road Traffic in Nagpur City, India

The main intention of research is to quantify and predict the noise level due to heterogeneous traffic conditions at critical junctions and highways. A study was carried out to assess the existing status of noise levels and its impacts on the environment with a possibility of further expansion of the city. Vehicular traffic noise levels measured during peak and non-peak hours at all selected locations were higher (71-76 dBA and 69.3-76.3 dBA) than the prescribed limits. The recognized amount of traffic and with the help of road geometry data, prediction of noise level is performed using modified Federal Highway Administration (FHWA) model, and the computed noise was compared with the measured one for assuring the relevance of this model for prediction of forthcoming noise. The outcome received from this model was nearer to the observed noise level, having a percentage error of +/- 3%, the best fit lines generated between them gives R-2 of 0.457. In this study measured and computed noise exposure levels were depicted with the help of contour maps. Octave band spectral analysis reveals that the interrupted traffic flow is above the free flow traffic and realized that the contribution of two wheeler and cars/jeep are mainly responsible for a generation of noise level at both the lower and higher frequencies, it also signifies that the FHWA model is convenient to be used for Indian circumstances.