Corridor preservation for Outer Sydney Orbital road and rail/M9, and Castlereagh Connection

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Corridor preservation for Outer Sydney Orbital road and rail/M9, and Castlereagh Connection

Future connectivity between Western Sydney and Central Coast/Illawarra
Early-stage proposal (Stage 1)
Western Sydney, Illawarra, Central Coast, NSW
Fast-growing cities
Corridor Preservation
Problem/Opportunity timeframe
Near term (0-5 years)
Proposed By
NSW Government
Date added to the IPL
17 February 2016


Western Sydney, as well as areas north and south of Sydney, will need to accommodate large travel demand  increases due to significant population  and employment growth.

By 2031, an additional 140,000 people  are expected to live in the Illawarra and Central Coast regions, and an additional 1 million people in Western Sydney. The broader Western Sydney Employment Area is expected to accommodate 378,000 new jobs in the long term.

Traffic modelling undertaken as part of  the 2015 Australian Infrastructure Audit indicates that in 2031 parts of the existing outer Sydney road network will be at or above capacity, which is expected to result  in congestion and long travel times.

In the absence of long-term planning and corridor protection, future infrastructure provision would be complex and costly.

Modelling by Infrastructure Australia in 2017 estimates the net cost of protecting and acquiring the corridor between Richmond and east of Picton as $0.3 billion (2016 prices) using a 7% real discount rate.


In March 2018, the NSW Government  publicly exhibited a planning study to identify and ultimately preserve a preferred alignment for a multi-modal transport  corridor in Western Sydney, comprising a motorway, a north–south freight rail line, and, where practical, integrating a north–south passenger rail line.

The NSW Government has confirmed the preservation of the Castlereagh corridor (originally reserved in 1951) to allow for future improvements to road connectivity and transport efficiency within Greater Sydney and to regional areas west of Sydney.

Next steps

Proponent to develop potential investment options (Stage 2 of Infrastructure Australia’s Assessment Framework).