Noise Reduction by Urban Traffic Management

This papers reviews the main studies on traffic management and analyzes the numeric noise results of several current options. It was found that between speed cushions or humps the noise reduction is about 1 to 2 dB(A) but there is an increase of 2 to 3 dB(A) (depending on vehicle and hump types) and annoyance (harsh deceleration and acceleration) near the humps. Speed reduction induced by diminution of road width can lead to a noise reduction of 1 to 3 dB(A) especially if it is combined with other traffic management measures. Road noise models usually introduce a penalty up to 3 dB(A) near intersections. The introduction of traffic lights coordination or roundabouts can locally reduce the noise from 1 to 2 dB(A) (free flowing according to interrupted traffic). Speed limitation (from 50 to 30 km/h) induces a noise reduction of 2 to 4 dB(A) for passenger cars and 0 to 2 dB(A) for heavy vehicles (and 2 dBA more for the maximum noise level). Other measures investigated are the selective limitation of the traffic and the low noise driving. 1