Noise and road traffic measurements have been made at a random selection of homes in england, stratified both by geographic region and population density. The sample was representative of the home conditions of the adult population of england. Average noise levels at the homes were distributed approximately in a gaussian distribution with a standard deviation of about 8 db(a). the distribution of the logarithm of 24 hour traffic flow was also approximately gaussian with a standard deviation of 0.75. A comparison with traffic census data indicated that flows in residential roads were lower than average. The data showed no significant noise differences between the regions of england except for london which was about 7 db(a) noisier on average than the other regions. Outside london, average noise levels varied systematically with population density and this variation could be explained almost completely by variations in average traffic flow and distance to the road. Even after allowance had been made for the higher traffic flows in london, sound levels were about 6 db(a) noisier than in the other conurbations. No london homes were found with levels of l10 (18 hour) below 50 db(a) whereas in the other conurbations approximately 25 per cent of homes experienced these levels. This difference was attributed to the effect of major traffic routes in london and could explain the high levels measured there. (Author/publisher)
Samenvatting