The final piece of a multibillion-dollar motorway connection to Sydney’s new international airport is set to be opened to motorists on Sunday, four months before the first passenger flights take off.
The major interchange will link the tolled M7 motorway at Cecil Hills, near Bonnyrigg, to the M12 motorway, which will be free for motorists and provide them with a connection to Western Sydney Airport.
The opening comes after the ribbon was cut in March on the main section of the 16-kilometre M12, which took four years to construct.
The $2.1 billion M12 is two lanes in each direction and comprises 17 bridges, the longest of which is a 700-metre span over South Creek. Up to 30,000 vehicles a day are forecast to travel along the M12.
Sources close to the project confirmed that the ribbon would be cut on the M12-M7 interchange this Saturday, followed by it being opened to motorists on Sunday. NSW Roads Minister Jenny Aitchison’s office declined to comment.
The bill for construction of the M12 has risen steadily – mostly under the previous Coalition government – since late last decade, when it was budgeted at $1.25 billion.
In 2019, the cost of acquiring properties was cited as a major reason for the budget rising to $1.8 billion, while design changes two years later pushed it to more than $2 billion.
Toll road operator Transurban has also widened a 26-kilometre stretch of the M7 motorway from two to three lanes in either direction. It required 41 bridges to be widened along a stretch between Richmond Road at Oakhurst and the M5 motorway at Prestons.
As part of a deal signed with Transurban several years ago, motorists will pay tolls on the M7 for an extra three years until 2051 to widen the highway and build the new interchange with the M12.
Delays to the opening of a 23-kilometre metro rail line to Western Sydney Airport have made the completion of the M12 motorway and junction linking it to the M7 more critical.
The metro line was originally meant to open at the same time as the airport, but a dispute between the NSW government and contractors building the project now means it risks being delayed until 2028.
Western Sydney Airport chief executive Simon Hickey said on Wednesday that the M12 was “really our front door”, while adding that other main arteries around the precinct such as the Northern Road had been upgraded.
Cargo flights will start at the international airport on July 26, followed by airliners on October 25 when a Jetstar A320 will become the first passenger plane to take off from the new aviation hub.
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Matt O’Sullivan is transport and infrastructure editor at The Sydney Morning Herald.Connect via X or email.