Work on the Sydney Metro West mega project is officially underway, set to create tens of thousands of jobs.
The Bays Station site is being prepared for the arrival of tunnel boring machines.
The project will help cut crowding on three major train lines and take tens of thousands of cars off the roads every day.
It will create more than 10,000 direct new jobs and around 70,000 indirect jobs.
Sydney Metro West will deliver new fully accessible stations at Westmead, Parramatta, Sydney Olympic Park, North Strathfield, Burwood North, Five Dock, The Bays and the Sydney CBD.
This once-in-a-century infrastructure investment will have a target travel time of about 20 minutes between Parramatta and the Sydney CBD, link new communities to rail services and support employment growth and housing supply.
The road works at The Bays, assessed and approved earlier this year, will allow the first of four mega tunnel boring machines to be in the ground before the end of 2022.
Sydney Metro is continuing to work through the shortlist process to appoint a consortia to deliver the first tunnelling package, the Central Tunnelling Package, which includes 11km of twin tunnels from The Bays to Sydney Olympic Park.
Due to the scale of this city-shaping mega project, the tunnelling and excavation works have been separated into geographically-specific contract packages between Westmead and the Sydney CBD.
The first tunnelling contract is expected to be awarded by the middle of 2021.