Traffic noise control by road surface treatment

The source of tyre/ road interaction noise is generally thought to be of considerable importance in the treatment of vehicle and traffic noise since, for most vehicles (motorcycles excepted) in a state of reasonable maintenance, it represents the major source of constant speed roadside noise for all speeds exceeding around 30 km/h. Consequently, once the behaviour of this particular source is understood, it may provide a practical avenue towards the economical control of vehicle, and therefore, traffic noise. A brief outline of some of the more recent data collected is given. Roadside noise data, monitored under typical Australian conditions, are presented for a range of common road surface macrotextures and tyre tread configurations. From there the trends in these data are quantified via regression analyses which are based on the air pumping noise generation mechanism. This has allowed application of the results to a consideration of vehicle noise control. A useful range of low noise design options is investigated. In particular, it is demonstrated that, due to the interactions between tyre and road, there would seem to be specific lower limits to the noise reduction that may be achieved by the control of road surface macrotexture alone. The economic consequences of these findings are also considered.