The Sydney Metro Northwest rail project is on target to be delivered at least AUS$500M (£271M) under budget.
The final pieces of track are being laid for the first stage of Australia’s biggest public transport project, where the last section of 52.5km of railway tracks has been installed.
Australian Premier Gladys Berejiklian said of the savings: “The major contracts for Sydney Metro Northwest were awarded in 2013 and 2014 and the project budget was set at $8.3bn (£4.5bn).
“Project costs are constantly refined during the construction process and, through good management, we’ve been able to realise significant savings – which will be used to deliver the $20 billion-plus (£10.8bn) Sydney Metro expansion,” Berejiklian added.
Over the past 22 months, 105km of steel rail was installed in the twin 15km tunnels between Bella Vista and Epping, on the 4km skytrain between Bella Vista and Rouse Hill, and at Sydney Metro HQ at Rouse Hill.
There were also 60,498 sleepers installed, 35,000t of ballast and 237,000t of concrete used in the track laying process alone.
On average, 300m of track was laid underground a week.
Tunnelling for the 15km tunnels, the longest railway tunnels to ever be built in Australia, was completed in January 2016.
Sydney Metro Northwest services will start early next year.