Waka Kotahi NZ Transport Agency has completed the installation of noise wall panels along the Southern Motorway (SH1) between the Greenlane and Ellerslie interchanges. The works were completed in May 2018 and have significantly reduced the disturbance caused to residents by motorway noise.
Nearly 1km of acoustic barrier was installed adjacent to SH1 between the Greenlane and Ellerslie interchanges. Divided into three sections, the project consisted of 233 three-meter-high panels to minimise the impacts of residential noise exposure.
Future noise walls in this area will be included in Waka Kotahi’s nationwide business case for noise barriers or low-noise surfacing. A policy is currently being developed for prioritisation of any improvement works, as funding for this is not presently allocated within the 2018-21 National Land Transport Plan (NLTP). Any future funding would need to be reviewed in the context of other competing activities, such as safety, resilience, and maintenance.
The core design philosophy was to create a seamless piece of infrastructure that responds to the overall road corridor, complimenting road structures, landscape and road scape and which also reflects the local land use and rich history of the area.
The result was a design which draws from the area’s history of early Māori settlers, who used wakas as their main form of transportation. As such, the motorway symbolises an awa (river), with the tiki, tuatara and takarangi elements illustrating spiritual warning and protection.
Acoustic barrier designs
Acoustic panel moulds
Specialist moulds were created to build each noise wall panel. The moulds contained a special resin, allowing each mould to be removed without sticking to the concrete. Moulds are one of the most efficient ways to create these panels, as they allow the designs to be replicated and altered easily.
