Heavy fog has caused a delay to the start of track activity at the Repco Mount Panorama 500.
The Battery World Aussie Racing Cars Super Series was to have got the programme underway with Practice at 07:20 local time/AEDT.
However, with low visibility around South Bathurst, including the race track, cars are waiting in the marshalling area as at 07:45.
It is understood that support category sessions may be compressed to make up time.
Gulf Western Oils Touring Car Masters was due to head out for Practice at 07:50, followed by Toyota Gazoo Racing Australia 86 Series Practice 1 at 08:20.
The first Supercars action is opening practice for the Dunlop Super2 Series scheduled for 08:55, while the Championship field is not due on track until 12:00.
UPDATE 09:15 AEDT: No track activity; Super2 Practice 1 delayed