Construction work will start on the new light rail project three weeks ahead of schedule, to enable less work to take place near major shops at Christmas.
The state government is also proposing to ramp up an advertising campaign to alert people to the disruption caused by the construction project, which will trigger widespread changes to bus services.
"The bad news is we are starting early," Roads Minister Duncan Gay said. "The good news is that we are moving the major and the complex stuff away from that pre-Christmas period," Mr Gay said.
Wholesale changes to bus routes through the city start on Sunday, October 4. On Monday, October 5, the government will close some lanes of George Street to enable works on moving underground utilities to start.
This work had previously been scheduled to take place from October 23, but the timetable has been shifted to clear road and pedestrian space in late December.
"Please come and shop in the CBD during the festive season," the Transport Minister, Andrew Constance, said. "We are doing everything possible to ensure that pedestrian access is maximised outside of these businesses."
The government has already allotted about $4 million to advertise the construction project, alerting pedestrians, businesses, and public transport users of the disruption to come. That spending will increase to about $6 million, Mr Constance said, while adding that he did not apologise for communicating the scope of the changes.
On the government's current timetable, major works between King Street and Park Street on George Street should be finished by Christmas next year, while trams on the new line are to be in service in late 2018 or early 2019.
"If I could sit here and put my hand on my heart and tell you there's not going to be problems, I'd be lying to you," Mr Constance said.
The coordinator general of the CBD transport, Marg Prendergast, said access to driveways, footpaths and a mid-block crossing would be maintained during the construction program.
