Analysis of Noise Level by Change of Vehicle Speeds at Different Types of Vehicle

A noise level differs from change of vehicle speeds at the real road condition. Typically, a noise level increases as the vehicle speed increases. In this study, the change of noise level was investigated at different vehicle speeds using four different types of vehicle. The noise was measured as increasing vehicle speed of 10km/h using both pass-by method and NCPX methods. This noise measurement results were compared with the simulation results obtained from Cadna-A program. Based on the analysing results, for by-pass method, 1.5dB(A) increases as 10km/h of the vehicle speed increases. While, for NCPX method, 2.3dB(A) increases as 10km/h of the vehicle speed increases. NCPX method shows that the noise level is significantly increased by the speed of passenger car and SUV. However, pass-by method shows that the noise level is significantly increased by the speed of bus and dump truck. Therefore, it could be used to manage the vehicle speed at downtown and living area in order to reduce the traffic noise on the road.