*This is an abstract only. No full paper was prepared for this abstract.* The Lane Cove Tunnel (LCT) is an important infrastructure link in New South Wales (NSW) and runs from the end of the Gore Hill Freeway at Artarmon at its eastern extremity, to the end of the M2 at North Ryde at its western extremity. The LCT is 3.6 km long and generally consists of twin two/three lane unidirectional tunnels running largely under Epping Road from just east of Mowbray Road, west to the western end of the Gore Hill Freeway. The tunnel opened in early 2007._x000D_
The presentation will provide a summary of the traffic and emission modelling performed for selected representative surface road sections in the vicinity of the Lane Cove Tunnel. An assessment of the predicted impact of vehicle emissions on ambient air quality in the corridor as a result of changed traffic conditions due to the tunnel opening will be presented._x000D_
The traffic modelling and emission calculations were undertaken for the following two scenarios: Year 2006 - Lane Cove Tunnel no-build option, and Year 2006 - Lane Cove Tunnel build option._x000D_
Vehicle emission calculations for the four main pollutants from vehicles: CO, VOC, NOx and PM10 on the surface roads in the vicinity of the Lane Cove Tunnel were performed using the predicted daily traffic for the two cases (no-build and build)._x000D_
The analyses indicated that the vehicle emissions for all pollutants are expected to significantly reduce in the corridor with the building of the Lane Cove Tunnel, including the areas in the vicinity of all tunnel portals, when compared to vehicle emissions for the no-build case. As a result of the decreased vehicle emissions on the surface roads, the study concluded that the actual ambient air quality is expected to improve in the corridor including the tunnel portal areas after the Lane Cove Tunnel opening.