EFFECTS OF ROAD TEXTURE ON TRAFFIC NOISE AND ANNOYANCE AT URBAN DRIVING SPEEDS

This paper describes work that has found that insufficient allowance is being made for road surface effects on traffic noise in New Zealand urban areas where vehicle speeds are typically 50 kilometres per hour. Therefore low noise road surfaces could have much greater benefit in reducing community annoyance with noise in urban areas than was previously thought. A vehicle cruise-by technique, which captures both the noise level and a spectral distribution of the noise from test vehicles and samples of actual vehicles within vehicle streams, was used to measure the noise from a range of road surfaces. It was found that, at 40-50 kilometres per hour , when compared to dense graded asphalt, the most commonly used road surfaces (the chip surfaces) may be 3 to 6dBA noisier for cars, and 0 to 2dBA noisier for trucks. These effects are much larger than is anticipated by commonly used road noise models. (a) For the covering entry of this conference, please see ITRD abstract no. E208431.