Great Western Highway Duplication

Great Western Highway Duplication

In March 2019, the NSW Government announced that it would duplicate the Great Western Highway, from Katoomba to Lithgow over the next 10 years. 

The NSW Government will commence construction on upgrades between Katoomba to Mount Victoria, including:

  • Medlow Bath upgrade.
  • Mount Victoria Bypass to Little Hartley.
  • Jenolan Caves Road to Forty Bends.

And will commence planning upgrades at:

  • Katoomba to Medlow Bath.
  • Medlow Bath to Blackheath.
  • Little Hartley to Jenolan Caves Road.
  • Forty Bends to South Bowenfels.

A tunnel at Blackheath is also planned. The design of the tunnel includes three possible portal options: 

  • A northern portal next to the Mount Boyce Heavy Vehicle Safety Station;
  • A short southern tunnel portal option located in Sutton Park; and
  • A long southern tunnel portal option south of Evans Lookout Road.

The NSW Government is also investigating an 11-kilometre tunnel linking the two tunnels (previously planned to be separate) at Blackheath and Mount Victoria.

Key Dates

2022 Expected Construction Commencement at Medlow Bath
2030 Expected Construction Completion of ten year program

Funding contributions

Federal Government
NSW Government


Procuring Agency: Transport for NSW
Related contracts:
Detailed Design and Environmental Assessments (Eastern Section)
Successful Tenderer - Aurecon.

Detailed Design and Environmental Assessments (Western Section)
Successful Tenderer - An Arcadis-Jacobs Joint Venture.


Mar 2020 Transport for NSW called for tenders to prepare a Strategic Business Case and Economic Analysis for priority projects in the Great Western Highway Upgrade Program. The successful bidder may also be required to prepare two Final Business Cases for priority projects, as determined during the development of the strategic business case. The tender process is open until 9 April 2020.
May 2020 Registrations of Interest (ROI) were invited to finalise a Preferred Concept Design, prepare a Detailed Design and complete an Environmental Assessment for the Medlow Bath section of the project.
Aug 2020 TfNSW opened registrations of Interest for the design and preparation of environmental assessments for the Great Western Highway duplication.
Sep 2020 MRB Technical Services was appointed by NSW Government to review and refine the strategic design of the project.
Oct 2020 Transport for NSW selected a tunnel as the preferred option for the Greater Western Highway upgrade at Blackheath.
Dec 2020 An Aurecon and Arcadis-Jacobs Joint Venture were appointed to design the eastern and western sections of the project respectively and prepare environmental assessments.
May 2021 The Federal Government announced $2 billion in additional funding for the Great Western Highway Upgrade in the 2021-22 Federal Budget. The NSW Government also announced that it is investigating linking the tunnels at Blackheath and Mount Victoria to create a single 11-kilometre tunnel for the project.
Estimated Total Cost
Procurement approach
Unconfirmed |
New South Wales |
Infrastructure Australia status
Priority Initiative (near-term, 0-5 years)
Project website
Project website
Government resources
Community Engagement