Road traffic noise assessment and modeling of Sambalpur city, India: A comprehensive, comparative and complete study

The road traffic noise environment of the city of Sambalpur, Odisha, was appraised in the present study. Noise pollution was analysed in 16 different squares during six different specified times (7 -10 a.m., 11 a.m.-2 p.m., 3 -6 p.m., 7–10 p.m., 10 p.m.-1 a.m., 3 -6 a.m.) to assess the level of noise pollution of the city. Noise descriptors such as L₁₀, L₅₀, L₉₀, Leq, TNI (Traffic Noise Index), NPL (Noise Pollution Level) and NC (Noise Climate), Q (Traffic Volume), P (Truck-Traffic Mix Ratio), Lden were worked out to reveal the extent of noise pollution due to heavy traffic in this city. Noise levels at all the road sections exceeded the standard ambient noise levels prescribed by WHO (70 dB during day time and 55 dB during night time). Even the minimum NPL and TNI values were more than 98.7 dB and 104.7 dB respectively during day time. Chi-square (χ²) test was also computed for investigated squares at different time intervals to infer the level of significance. Comparison of predicted/simulated noise level with that of the actual measured data demonstrated that the Burgess model used for the prediction has the ability to calibrate the multi-component traffic noise and yielded reliable results close to that by direct measurement. Moreover, individual contribution to environmental noise by the air horn of different motor vehicles was also assessed in and around this city during day time. The episodic and impulsive noise levels of different types of vehicles were more than the traffic noise-limit. A questionnaire survey amongst 502 local inhabitants had also been carried out to gather information about their perception on noise pollution.