By Ashley Karen
The £2bn ‘complex’ tunnel interchange scheme, Rozelle project, characterized as one of the most complex underground junctions in the world, has been inaugurated in Sydney after three years of construction work.
The A$3.9bn (£2bn) Rozelle interchange is a 33km project and contains 24km of tunneling beneath the Rozelle Rail Yards.
The interchange has three levels of tunnels within which “funnel” traffic from a dozen different entrances, comprising the City West Link, the Iron Cove Bridge, the Anzac Bridge, and the M4-M8 link.
John Holland, a tunneling specialist, and CPB Contractors Joint Venture, part of CIMIC Group, have constructed the Rozelle Interchange.
The NSW government seeks to link the interchange with the Western Harbour Tunnel project. Work has started on the second stage of the latter scheme, which intends to relieve congestion on the Sydney Harbour Bridge. Also, the project is a 6.5km tunnel that will link the Warringah Freeway in North Sydney with the Rozelle Interchange and is envisioned to be finished in 2028.
The first stage of the Western Harbour Tunnel contained 1.7km of tunnels for the southern section from Rozelle to Birchgrove and will be finished in 2025. However, stage 2 will include the Warringah connection construction, which is predicted to take five years.
The Rozelle Interchange construction started in 2020 and reached the halfway mark in 2021. It forms the final stage of the WestConnex project, which includes a 33km “traffic light” motorway network.
Most of the total 33km is underground, as the New South Wales (NSW) government has embraced programs to remove congestion by taking roads underground, opening up surface space for new development, and improving air quality.
WestConnex has four major stages; the new M4 motorway opened in July 2019, incorporates 5.5km of tunnels and links Haberfield to Parramatta.
The M8, which opened in July 2020, comprises 9km of twin tunnels at the M5 at Kingsgrove to a new interchange at St Peter’s, with 6ha of new open space, and was constructed on a remediated former landfill site.
The M4 and M8 new extension opened in January 2023, connecting the M4 at Haberfield with the M8 at St Peter’s, with future links to the Anzac and Iron Cove bridges through the Rozelle Interchange.
