Development and Evaluation of a Frequency Related Source Intensity Prediction Model of the Traffic Acoustic Noise
Two expressway sections including the south section of the beltway in Xian and the start section of the Xi'an-Lantian expressway were selected in this study. By monitoring the acoustic noise level at different frequencies and vehicle speeds, a frequency related source intensity prediction model of the traffic acoustic noise was developed. Experimental results show that the spectrum distribution varies greatly among different kind of vehicles. The noise source intensity produced by large vehicles mainly distribute in low-frequency area. Different from large vehicles, medium vehicles mainly produce medium or high frequency noise, especially when the vehicle's speed is above 60 km/h. When the vehicle's speed is below 60 km/h, the acoustic noise intensity produced by the medium vehicles is relatively weak. The accuracy of the source intensity prediction model is further proved by comparing the predicted data, determined data, and the data obtained in the literature under similar experimental conditions.