A study has been made of the noise of vehicles on a wide range of road surfaces. The object of the study was to investigate the relationship between noise and the frictional properties of the road surface. It was found that there were no significant tonal differences between noise from concrete and that from bituminous surfaces. On both types of surface the peak noise level from light and heavy vehicles is a function of the percentage change in braking-force coefficient which is a measure of the effectiveness of the surface texture in retaining skid resistance at high speeds. For a given percentage change in braking-force coefficient, the noise is the same for any type of concrete or conventional bituminous surface. Values have been derived for incorporating surface noise into the prediction of l10 levels for various types of road. Experiments on the TRRL test track showed that the noise of cars rolling on transversely-grooved concrete was a function of the groove cross-sectional area. A concrete road subsequently constructed using deep, narrow, groove-formers to give a durable texture with low groove cross-sectional area had an initial noise level that was within the limit of accuracy of the value predicted from the amount of texture imparted to the surface. (Author/publisher)
Samenvatting