Traffic noise introduced by vehicles operating on highways is a major source of discomfort and concern for the population in the vicinity. A number of noise prediction models have been developed over the past 30 years that attempted to model the road condition under study. But, as traffic flow characteristics, road characteristics, geometric parameters etc. are different from what are prevailing in those developed countries, these models cannot be applied directly in its present form. There is a need to check its transferability in order to make it suitable for the prediction of traffic noise on Indian highways. In the present work, the traffic noise on NH – 06 passing through Chhattisgarh have been observed. The traffic noise prediction is done with the help of Federal Highway Administration Model (FHWA) using the traffic volume and speed data recorded at different sampling stations.
This paper tried to check the geographical transferability of the FHWA model on NH-06 passing through Chhattisgarh. In doing so, the study area of NH-06 has been divided into four locations, these locations are Supela (location 1), Power house (location 2), Bhilai III (location 3), and Charoda (location 4). Traffic noise is measured directly with the help of a sound level meter SL 4023SD. It is then compared with the noise level predicted using the FHWA model in terms of the percentage difference and absolute difference. Regression analysis is then performed to get modelled equations. Following are main points regarding the study undertaken for NH-06. The absolute difference between the observed and the predicted traffic noise level is observed in the range of 2.94-6.88 dB(A) for location 1, 0.266-4.47 dB(A) for location 2, 0.58-5.2 dB(A) for location 3, and 0.33-6.3 dB(A) for location 4. As the absolute difference obtained at all four locations are in an acceptable range and the Coefficient of Correlation (R2 ) obtains a value between 0.8 to 1.0, which depicts a good relationship, and therefore, the model can be geographically transferable. The validity of model is checked through statistical analysis using paired t test and also justifies the model developed for NH-06, as the calculated value of t obtained is less than the critical value for a given confidence interval.
