Air quality

The RTA is committed to monitoring and managing air quality within Sydney’s tunnels, as well as within surrounding communities. Motorway tunnels take cars off local streets, improving air quality. Inside the tunnels, sophisticated measurement and ventilation systems ensure that air quality meets stringent regulations governing emissions levels.

How the RTA manages air quality

Air quality in Sydney’s motorway tunnels is managed by
flushing the tunnel with fresh air.  This dilutes the pollutants emitted from vehicles as they travel through the tunnel.  Mixing large volumes of fresh air with the vehicle emissions ensures that the concentration of pollutants remains within set limits. 

Fresh air is drawn into the tunnel at the portals (vehicle entrances and exists) by fans which also move the air along the tunnel at high speed. In some tunnels additional fresh air is drawn into the tunnel using large fans at an air intake point.

Once air has travelled along the tunnel it is expelled via a ventilation building. Typically, a ventilation building contains large fans which blow the tunnel air out at high speed. Ventilation buildings are designed to ensure exhaust is well dispersed. This prevents pollutants from accumulating at ground
locations around the building.

Air quality and the Lane Cove Tunnel

Ventilation in the tunnel

The Lane Cove Tunnel has two ventilation buildings. One at the western end of the Lane Cove West Industrial Park on Sirius Road and one at the eastern end in the Artarmon industrial area, between the western end of Marden Street and the Pacific Highway.

In-tunnel air quality

Monitors in the Lane Cove Tunnel measure pollutant levels along the length of the tunnel. Air quality is also measured in the ventilation building.  The tunnel operator, Connector Motorways, carries out rigorous routine testing of the air quality in the tunnel. The air quality standards for the Lane Cove Tunnel were set down in the Planning Minister’s Conditions of Approval. Air quality data is available to the public on the Connector Motorways website - click here.

Local air quality

Between 2005 and 2010, Connector Motorways operated four local (or outside) air quality monitoring stations, including two ‘community-based’ stations, one at Artarmon Public School and one at the Hallam Avenue tennis courts. Ground level monitoring stations were also located at Lane Cove Country Club Golf Course and Magdala Park North Ryde. Carbon monoxide, nitrogen oxides, volatile organic compounds (VOC) and particulate matter were measured and reported publicly. Readings above the Department of Environment, Climate Change and Water (DECCW) approved goals for pollutants triggered reports to the RTA, the DECCW and NSW Health within 24 hours.

All external air quality monitoring stations ceased operation on 1 April 2010 in accordance with the Minister for Planning's conditions of approval for the project.