The build on the second stage of Parramatta's light rail project is set to get underway after a $2 billion budget investment, but the NSW government claims it is too early to announce when the long-awaited line will open.
The project's multi-billion dollar Stage 2, expected to service a population of more than 280,000 by 2041, will include 14 stations and run 12km from the Parramatta CBD to Olympic Park.
On Monday, the government said it would allocate the $2 billion in this month's 2024/25 budget, allowing construction to start after recent planning and environmental approval.
The project has been without a price tag since being announced by the former Liberal government in 2017.
Premier Chris Minns said the new stretch of light rail would carry 28,000 passengers daily by 2026, but did not specify when the line would open to the public.
"We can't give a date on that this morning and we're not trying to be opaque about that," Mr Minns told reporters from Camellia in Sydney's west.
"The reason for the money in the NSW budget to establish the business case is so we can get both time and cost nutted down."
Other stations, including one at Rosehill, could be added if the government's controversial plan to develop Rosehill Racecourse for housing went ahead, the premier said.
Transport Minister Jo Haylen said most of the budget spend would go on enabling work for the line as well as on an updated business case.
Passengers will be able to travel from Sydney Olympic Park to the Parramatta CBD in 37 minutes, the government says.
Last year's state budget allocated Stage 2 an extra $200 million to expedite the project's planning processes and ensure construction started in the government's current term.
Stage 1 of the project, which connects Westmead to Carlingford via the Parramatta CBD with 16 light rail stops, is in testing and on track to service commuters in coming months, the government says.
Urban Development Institute of Australia NSW chief Stuart Ayres welcomed the project in unlocking more housing and employment opportunities.
"Key city shaping projects like these, are essential transport enhancements that can deliver a double economic dividend, unlocking thousands of jobs and the delivery of new homes close to transport links," the former Liberal trade minister said.
But the Greens called on the government to extend Stage 2 an additional 3km from Carter Street to Lidcombe Station to ease congestion and support the expected population growth in western Sydney.
"Not extending the light rail all the way to Lidcombe station is a huge missed opportunity to bust congestion in this rapidly growing area of Sydney," Greens MP and transport spokesperson Cate Faehrmann said.
Ms Faehrmann described the Carter Street precinct as a "random endpoint" not closely linked to an interchange or junction, employment or retail spaces, or other public transport options.
"For just an additional 3km of rail line, significantly greater benefits would be realised for many more people than the current route," she said.
