Acoustic classification of road pavements: ranking differences due to distance from the road

In a majority of industrialised countries, traffic noise abatement is consi dered as essential. Road pavements can contribute to this challenge. Resear ches carried out in the past ten years have made it possible to rank the ac oustic performances of pavements for short range conditions in terms of A-w eighted vehicle pass-by sound pressure levels L-Aeq. This classification ha s now to be confirmed for long range situations in terms of A-weighted equi valent sound pressure levels L-Aeq, an indicator currently used for environ mental nuisances. This is the purpose of this paper, which presents theoret ical and experimental results concerning the ranking changes at various dis tances from the road and for three kinds of acoustically different pavement s. Preliminary results show that the ranking close to the road seems to be preserved at distances up to 200 m with some differences depending on the c onsidered reference period (6 h-22 h or 22 h-6 h) which can be attributed t o weather and traffic conditions.