Westlink M7 motorway

Client Name
Sydney’s Westlink
Sydney, New South Wales, Australia
  • Acoustics & vibration


Sydney’s Westlink M7 Motorway opened to traffic in December 2005 (six months ahead of schedule):

  • The motorway runs for 40 km (25 miles), and connects three other major motorways in Sydney (M2, M4, M5); it is situated within a high growth industrial and residential corridor
  • The motorway includes 17 access points, 38 over-passes and under-passes, 144 bridges and a 40 km uninterrupted cycling and walking path.

The motorway’s route runs within a narrow industrial and residential corridor experiencing strong growth (almost 5,000 residential dwellings lie in close proximity to the route). Accordingly, the mitigation of noise and vibration (during both the construction and operational phases of the project) was identified early in the design process as one of the project’s key environmental factors.

Ultimately, SLR’s noise and vibration consultancy, which spanned the full duration of the project, included the design and optimisation of 160,000 m2 of noise walls and over 1,200 property treatments.


SLR undertook the following works:

  • Tender Phase: Tender noise mitigation costings (noise walls, low noise pavement and property treatments)
  • Design Phase: Baseline noise surveys; operational noise predictions; attenuation recommendations covering pavement (low-noise options), noise walls and at-residence insulation; maximum noise level assessment (Compression Brake Noise Minimisation Strategy); Construction Noise and Vibration Management Plan
  • Stakeholder Engagement: Community consultation (pre and during construction)
  • Construction Phase: Construction noise and vibration monitoring
  • Post-Opening Phase: Post-compliance (operational) noise monitoring and residual property treatments.