Opening date revealed for Sydney’s underground spaghetti junction

Australia’s most complex underground motorway junction is set to be opened in two weeks, testing motorists’ ability to navigate 16 kilometres of road tunnels beneath inner Sydney.

Under plans for the Rozelle interchange, November 24 – a Friday – has been earmarked for the project’s ribbon cutting by politicians, and the tunnels opened to motorists within the following two days, according to sources close to the project who requested anonymity due to the matter’s sensitivity.

As a precaution, the following weekend – in early December – has also been pencilled in for the opening if further testing and commissioning is needed, or the earlier date is derailed by unforeseen events such as wild weather.

Sydneysiders got their first look inside the Rozelle interchange last Sunday ahead of the opening to motorists.Credit: Edwina Pickles

The government has repeatedly said the junction – the final part of the $17 billion WestConnex toll road – will be opened by the end of this year but has declined to provide an exact date.

Roads Minister John Graham said in a statement that he would “shortly be able to confirm an opening date” for the interchange and other information motorists would need to use the motorway tunnels.

“Rozelle interchange is now in its final phase of commissioning with ongoing work including the testing of incident response, ventilation and IT systems,” he said.

He did not answer questions about whether a toll-free period will be put in place after the interchange opens.

In 2017, a month-long holiday from tolls was introduced when a widened section of the M4 motorway between Homebush and Parramatta was opened as part of the first stage of WestConnex. Other motorways such as the Cross City and Lane Cove tunnels have had toll-free periods.

Congestion warning for drivers

Motorists have been warned to expect traffic congestion at key merge points for the Rozelle interchange during morning peaks on the City West Link and Victoria Road when the interchange opens.

Earlier on Thursday, Graham told a parliamentary hearing that it might take motorists as long as six months to get used to navigating the new interchange. “That might be slightly quicker or longer. It should clear up ... after that,” he said.

About 100,000 vehicles a day are forecast to travel through the underground interchange.

In an attempt to avoid major disruptions, the government released last week a series of animations to help motorists navigate the tunnels beneath Rozelle to scores of destinations.

The interchange connects the M4 and M8, the Anzac Bridge, City West Link and the Iron Cove Link, and will eventually link to the planned $7 billion Western Harbour Tunnel from Rozelle to North Sydney. The latter is due to open in 2028.

WestConnex not the silver bullet

The previous government committed to making a stretch of Victoria Road between Iron Cove Bridge and The Crescent wider for footpaths and cycle lanes after the Rozelle interchange opened. A 1.1-kilometre tunnel bypass of that part of Victoria Road forms part of the interchange.

Graham said one of the challenges was that repeated promises had been made to turn Victoria and Parramatta roads into “Parisian boulevards” as WestConnex was progressively opened, but traffic modelling he had received since becoming minister did not support them.

“The traffic modelling makes it clear it may be some time [for the plans to be fulfilled]. The opening of the Western Harbour Tunnel should give us an opportunity to reset in a more permanent way,” he told budget estimates.

By the numbers

• Almost 17 kilometres of motorway tunnels and 7 kilometres of mostly ventilation passages.
• The tunnels required 1.74 million metres of cabling to be laid.
• Almost 7 million tonnes of earth excavated.
• Installation of 132 jet fans, 335 emergency phones and 7400 lights.
• Nine electricity substations built.
• The project has required 38 traffic changes on nearby roads since 2019.

Quizzed on whether the government’s planned $60 weekly toll cap applied to every driver in NSW, Graham said he would release more information about the arrangements closer to when the policy came into effect on January 1.

“We indicated in the election ... that there would be audits, that there would be careful administration around the scheme, and I’ll be outlining those to the public in detail prior to the first of January,” he said.

“It’s complex delivering this toll relief.”

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