Tire-Pavement noise characteristics by traffic level and vehicle speed using CADNA-A software

In order to quantify traffic noise in accordance with changing vehicle speed, vehicle speed limit, traffic volume, heavy vehicle ratio, and the geometric conditions have to be concerned. However, the Pass-by method which is most common conventional test method has a limitation. It is difficult to quantify a traffic volume because of control both vehicle speed and real time changed traffic volume. Therefore, a noise change is required to predict using a variety of noise simulations and it needs to be verified at field test in the future. In this study, Cadna-A software was used to analysis noise near road as changed vehicle speed. The analysis results shown that the noise level of 40km/hr speed limit was lower than 110km/hr speed limit with 4.6dB(A). It indicates that the noise reduction effect of slow-speed section was greater than that of the high speed section depending on same traffic volume. In case of 50% less traffic volume, the traffic noise decreased about 3dB(A). However, the noise was increased 3dB(A) as the traffic volume increased by 100%. By measuring noise location, noise difference measured at 1.5m height between horizontal distance of 10m, and 20m is 4.6dB(A), noise difference measured at 15m height between horizontal distance of 10m and 20m decreases 1.7dB(A), and noise difference measured at 20m height between horizontal distance of 10m and 20m decreases 1.3dB(A). The suitability of the results from this study should be examined with the actual field test results further.