Development of a road traffic noise prediction model under uninterrupted traffic flow conditions

Abstract

The main objective of this study is to develop a noise prediction model under uninterrupted traffi c fl ow conditions. In this study, Bangalore city in Karnataka, India, was selected as the study area. The study locations are so chosen as to represent the different zones within an urban area like residential zone, commercial zone, silent zone and heavy traffi c zone. Traffi c noise was measured using the Leq index with an A-weighted scale of decibel unit for a 1-hour period at each study location. Based on fi eld observed traffi c data, a multiple regression noise prediction model was developed by considering all major causative factors. In the process of model development, a mean standard error of 2.32 dB(A) with r2 value of 0.82 was observed. The validation of the model was done by collecting traffi c data from Mysore city in Karnataka, India. The results of the model validation indicated that the model is accurate to 2.6 dB(A) with r2 value of 0.78. Statistical analysis was also done using the paired t-test technique on predicted and observed noise levels. The results indicated that the t-statistical value of the model is less than the t-critical value. This means that the values predicted by the model fi t signifi cantly with the fi eld observed ones and that the independent variables used in the model provide a better explanation of the dependent variable (Leq). The model developed in this study was also compared with the Federal Highway Administration (FHWA) Traffi c Noise Model from USA and the prediction results indicated that the values obtained from the present model are in good agreement with the fi eld observed values than the FHWA model. Therefore, the present model can be used for managing urban road traffi c noise in the Indian context.