Continuous road traffic noise monitoring and aging of asphalt surfaces

摘要

A highway in Switzerland has been paved with two different types of asphalt surfaces one after the other. Next to each of the road sections two acoustic recording stations were permanently registering traffic noise levels over a time period of two years. In parallel, meteorological parameters had been monitored and road traffic had been counted automatically in terms of vehicle classes. The noise levels at both monitoring stations display significant and slightly different increases over the observation period. This indicates differences in the aging behavior between the two asphalt surfaces. Since the noise level variances due to dependencies on meteorological conditions and traffic distributions are larger than the anticipated changes due to the aging of the surfaces, a stratified sampling strategy has been successfully applied in the statistical analysis of the traffic noise data. The consideration of temperature effects on tire-road noise has been of particular relevance. Periodical measurement surveys of noise levels by means of a CPX-trailer and the statistical pass-by method and of in situ measurements of acoustically relevant road surface characteristics show significant temporal changes on both pavement sections that go along with the results from the permanent noise monitoring stations and offer some insight into the physical changes of the surface.