Noise and vibration

A detailed noise and vibration assessment was carried out to evaluate and predict the potential impact of the construction and operation of the M4-M5 Link, within the context that the existing noise environment is generally dominated by relatively high levels of existing road traffic noise.

Tunnelling noise

  • Properties located above or near the tunnels may experience some short-term ground-borne noise and vibration impacts while tunnelling takes place nearby although, in most cases, this would be less than 35 decibels (dBA) which is equivalent to a quiet library environment.
  • We would regularly monitor noise levels to determine their impact on surrounding residences. Feasible and reasonable work practices would be investigated to minimise noise emissions.

Surface work noise

  • Building and tunnelling often require the use of noisy, heavy machinery, and sometimes there is limited opportunity to mitigate sound levels. During construction, there may be some elevated noise levels around construction and tunnelling sites.
  • Temporary buildings and structures, such as offices and amenities, would be situated so they provide a noise barrier between the work sites and neighbouring areas, and we would construct noise barriers and acoustic sheds to house tunnelling activities, where possible.
  • All equipment would be shut down when not in use and non-tonal reversing beepers would be used on vehicles. Generally, surface work would take place during standard construction hours.  

Operational noise

  • We have undertaken modelling to predict noise levels after the project opens to traffic. The depth of the tunnels means it is highly unlikely that residents located above the tunnels would be able to hear or feel any vibration from the motorway once it is operational.
  • On some sections of WestConnex, mitigation measures, such as the installation of noise walls, would be investigated to reduce the impact of surface traffic noise.  When this approach is not feasible or reasonable, properties may be eligible for acoustic treatments to mitigate noise impacts. Our teams would discuss this option directly with relevant property owners.

    Further details on noise and vibration impacts are provided in Chapter 10 of the EIS.