Evaluation and Forecasting of Highway Traffic Noise in the City of Nagpur, India

The noise levels in Indian cities are largely affected due to increase in the number of vehicles and growth of the transportation sector in the past few years. Transportation is crucial owing to Nagpur’s strategic location in central India. The City is linked with four metros Viz. Mumbai, Delhi, Kolkata and Chennai through roads, rails, and air. It’s also a major conjugation for roadways as India's two national highways, Hajira-Kolkata (NH-06) and Kanyakumari-Varanasi (NH-07) are passing through the city. The main objective of this study is to assess and predict the traffic noise levels of uninterrupted traffic flow on prominent highways, and an attempt has been made to develop noise maps to represent an overall noise scenario of the city. Noise modelling and prediction are performed using a modified Federal Highway Administration (FHWA) model. Substantial correlation has been obtained between the measured and estimated noise levels, which gives R² of 0.503 having an error band of ±3.8% with respect to the observed noise levels. Octave band spectral analysis reveals the dominance of noise emission levels in the medium and high-frequency range. This study perceives the observed equivalent noise levels at all the locations during the day and night hours exceeds up to 7.8 dB and 19.6 dB respectively, when compared with the permissible limits prescribed by National standard and signifies that the FHWA model is suitable for Indian road traffic conditions.