concern in the light of the incipient, rapid growth of road traffic and the expected development of industry.
It should be noted that data on noise from the different countries are often not obtained by the same method or using the same descriptors. In general, models have been used which are based on noise measurements and acoustical calculations on a limited number of typical locations. The results are then extrapolated to the whole country. The accuracy and representability of such models vary from country to country and some of them appear rather simplified. The designation of specific source categories for noise also varies (eg, transport, industry, tourism, etc). For these reasons statistics from different countries should be compared with caution.