The noise from road traffic affects large numbers of people living in the vicinity of State Highways and arterial roads. An increasingly important aspect of developing traffic noise reduction measures is the definition of ‘quiet’ road surface types and their application in affected areas. This project, undertaken in 2004–2005, identifies the noise effect that different low macro-texture bituminous mix road surfaces, such as asphaltic concrete, slurry seal, open graded asphalt and stone mastic asphalt, have on road traffic noise at urban driving speeds and at open road speeds.
Significant noise variations, of the order of 2 to 3 dBA, could occur between different bituminous mix road surfaces within the same generic type. While noise reductions as small as 1 to 2 dBA were previously regarded as too small to be significant, it appears that such reductions could actually be of considerable benefit to the community living adjacent to busy urban roads.
Selecting a quieter road surface type when resealing can be a highly effective measure if roading engineers wish to reduce traffic noise.