Air Quality

Tunnel Ventilation & Air Quality

While motor vehicle emissions are a source of air pollution, modern tunnel ventilation design ensures sufficient air flows within the tunnel to meet air quality requirements and uses elevated ventilation outlets to disperse tunnel emissions high into the atmosphere and become indistinguishable from background levels.

The M4 East tunnel links the inner-west Sydney suburbs of Homebush and Haberfield and was opened to traffic on 13th July 2019. Air quality results gathered during the eight months following the opening of the M4 East tunnel, and prior to the first restrictions related to COVID-19, showed that air quality related to traffic exhaust emissions (represented by concentrations of oxides of nitrogen) substantially improved in the vicinity of the tunnel.

No worsening of air quality was observed at any M4 East tunnel monitoring locations. There was no detectable impact from the emissions through the ventilation outlets on local air quality. This information was obtained from the following report: NIWA Client report (

The Rozelle Interchange has two ventilation facilities with elevated outlets, located on City West link near The Crescent intersection and Victoria Road near Callan Street.

Under the conditions of approval for the Rozelle Interchange project Transport for NSW are required to install Air Quality Monitoring Stations (AQMS) around the elevated ventilation outlets. The stations will monitor background air quality for one year before the Interchange opens to traffic and two years post opening to detect and understand any changes to air quality. The monitoring stations measure concentrations of air pollutants such as carbon monoxide and nitrogen dioxide, as well as particulate matter within the air. The locations of these stations are chosen to collect the most accurate data have been agreed on with The Air Quality Community Consultative Committee (AQCCC).

Further information about Air Quality can be found on our Tunnel Ventilation Fact Sheet or by visiting: Air Quality Portal Home | Transport for NSW (RMS) | Community Analytics (

The Air Quality Community Consultative Committee

The AQCCC is an advisory group that provides input and advice on matters relating to air quality on the Rozelle Interchange project. The AQCCC’s role is to provide advice and share feedback on behalf of the local community on areas relating to air quality

Committee members review key operational and environmental documents as they relate to air quality, consider reports relating to air quality, provide input on complaints relating to air quality and share important monitoring results with their local community networks

The committee is made up of representatives from Transport for NSW, Inner West Council, WestConnex | Transurban and members of the local communities who live near the Rozelle ventilation facilities.