An artist's impression of the Green Square town centre when the project is complete.

An artist's impression of the Green Square town centre when the project is complete. Photo: Supplied

Australia’s largest development, Green Square, is happening. But those who already live there are raising questions about the future of the project, which took decades to conceive.

The Green Square development, about four kilometres south of the CBD, is home to more than 20,000 people. Over the next two decades they will be joined by 30,000 more residents and an estimated peak of 20,000 workers.

But those who live there now say the area is already a tangle of cars that only seems to intensify with every tower built. Ten more are due to begin this year and residents are asking if the area can cope. 

“It's constant now,” said Mark Woodbridge, who has lived in Zetland for five years.

Mr Woodbridge said his street of heritage houses, once designated solely for local traffic, has become a procession of construction trucks and city-bound cars that go “thump” over futile but ever-present speed bumps.

“To get a good night's sleep is impossible. A lot of people won’t even use their front rooms because of the noise,” he said.

Plans for a cutting-edge library, town centre and water recycling system are already in place. But more fundamental transport infrastructure is not on the horizon.

“Green Square was always something that was going to happen in the future,” said Patricia Forsythe, from the Sydney Business Chamber. “It’s clear now that the development has got ahead of transport.”

About 120 buses run through Green Square in morning peak hours. Many are already full upon arrival.

Projections suggest without alternatives the site will have to cope with some 80,000 vehicles a day, an increase of one-third.

Many of the 16,000 new homes proposed to be built will be outside of walking distance to the train station, which is itself becoming crowded.

In one of its last acts, the previous Labor government removed an additional fee for getting to Green Square station that has doubled the number of passengers using the station within three years.  

Professor Ed Blakely, an urban development expert from the University of Sydney, hails Green Square as a breakthrough for Sydney.

But he agrees that with a “poor” heavy rail system and without rapid transit to make owning a car unnecessary, transport will remain a chink in the plan. 

Lord Mayor Clover Moore has been warning for years that increased public transport is essential to the success of the development.

But council is holding out for a light rail link and has spent $40 million on land to lay its path.  

But the previous Labor state government quashed those plans.  And its successor has made no moves towards reviving them even as it unveils ambitious tram projects elsewhere.

Upon taking power, the Liberal government chided Labor for ignoring issues in Green Square. "You really do need to ensure that there is delivery of infrastructure at the same time as residential densities increase,” former planning minister Brad Hazzard said.

But his successor Pru Goward did not respond to questions about how that might happen.