Queensland's biggest infrastructure project, the Brisbane Cross River Rail, will open three months later and cost $6.3 billion, $960 million more than initially planned.

According to a recent announcement by the state government, unavoidable economic headwinds are to blame for the budget blowout, with an additional $848 million required to cover increased costs and $112 million allocated for acquiring more land at Roma Street.

However, Mr Bailey reassured the public that Cross River Rail remained the “best-managed” mega project in the country, stating that the cost increase was minimal compared to the Sydney Metro's $6 billion budget blowout. 

The minister further explained that external advice was taken to forensically analyse the cost increase.

“This is absolutely unavoidable; the economic headwinds are very strong,”  Transport Minister Mark Bailey said. 

“It's unavoidable to have impacts from the COVID pandemic, from La Niña, the Ukraine war, supply chain impacts.”

Cross River Rail is a 10.2km underground heavy rail network from Dutton Park to Bowen Hills, including 5.9km of twin tunnels under the Brisbane River and CBD. Installation of underground tracks has been completed in all sections of the twin tunnels.

Initially, the project was budgeted to cost $5.4 billion, but the updated figure is said to reflect unavoidable cost impacts beyond the state government's control. 

The underground heavy rail network is now expected to open to the public in the first quarter of 2026.