Noise Walls
In accordance with the Environmental Approval Conditions for the project, Main Roads and Southern Gateway Alliance were required to manage the traffic noise levels to the satisfaction of the Environmental Protection Authority and Western Australian Planning Commission.
To meet the requirements of this condition, a Noise Management Plan was developed in consultation with the Department of Environment and Conservation (DEC), which was based on the Western Australian Planning Commissions’ State Planning Policy 5.4 “Road and Rail Transport Noise and Freight Considerations in Land Use Planning”.
As part of the Noise Management Plan, an estimate was made of the anticipated traffic at opening and in 2031, and noise modelling was undertaken to identify the specific locations where noise mitigation measures would be required. In the majority of cases, this mitigation was provided in the form of open graded asphalt surfacing to limit noise from the highway. Where the target noise levels were still exceeded, a noise wall was erected to limit the noise levels experienced at affected residences to below the noise levels required by the WAPC planning policy.
The noise modelling considered factors such as the type and volume of traffic using the highway, road surface and profile and adjacent land use. Also taken into consideration was the volume and composition of traffic expected to use the highway, not only at the time of opening, but also that predicted in the year 2031.
The implementation guidelines for the WAPC Planning Policy also require that the actual noise levels are measured 3 – 6 months after the opening of the road to traffic. This is to allow traffic patterns to stabilise and the road surface to stabilise under normal operating conditions.
Whilst we are confident that the next series of tests will demonstrate that the noise walls are achieving the levels of attenuation required by the Noise Management Plan, any deficiencies encountered will be remedied by SGA.
To view an information sheet on noise walls please click here.