The Sydney Harbour Tunnel is a 2.3 kilometre, four lane underwater tunnel  running below  Sydney Harbour. The tunnel connects the Warringah Freeway on the northern side of Sydney Harbour to the Cahill Expressway, south of the harbour. It provides an alternative cross-harbour route, dramatically easing traffic congestion on the Harbour Bridge during peak travel times.

The Sydney Harbour Tunnel is owned and operated by the Sydney Harbour Tunnel Company.

For more information on using the Sydney Harbour Tunnel go to Using Sydney's Motorways.

Background

The Sydney Harbour Tunnel project was initiated in response to increasing traffic congestion on the Sydney Harbour Bridge and its approaches. The need to alleviate this congestion via the provision of an alternative cross-harbour route was identified in the Roads and Maritime Services Roads 2000 (Sydney Orbital) plan. However the cost of such a project was beyond the scope of Roads and Maritime Services budget. Therefore a proposal from the private sector to build and toll the Sydney Harbour Tunnel project was sought and accepted by Roads and Maritime Services.

Key features

• Increased public transport use.
  As part of the Sydney Harbour Tunnel project, a dedicated bus lane was introduced on the Sydney Harbour Bridge. This led to a marked improvement in city-bound bus services, which in turn led to higher uptake of public transport services. The end result is fewer carbon emissions, better local air quality and less congestion on our roads.
• State of the art safety features.
  The tunnel features state of the art surveillance and response systems for breakdowns and accidents. The CCTV system incorporates fixed and tilt/pan/zoom cameras to allow visual monitoring of both carriageways, plant rooms, tunnel portals and the toll plaza. Video images from all cameras are shown on a bank of monitors in the control room. When a breakdown is confirmed, an Roads and Maritime Services (formerly Roads and Traffic Authority) tow truck is immediately dispatched to the incident to assist.

Benefits for road users

• Reduced traffic congestion on the Sydney Harbour Bridge and its approaches.
• Faster commuter travel across the harbour.
• Faster and more reliable travel between Sydney's north and the airport. The Sydney Harbour Tunnel links traffic flowing from the north of the harbour seamlessly to airport routes.
• Improved access between the harbour crossings and Sydney's south-western suburbs. The Harbour Tunnel links to the M5 East and M5 South-Western motorways.

Benefits for public transport users

• A marked improvement to city bound bus services for residents on the north of the harbour, due to a dedicated bus lane introduced on the Sydney Harbour Bridge.