New South Wales Police have urged motorists to be vigilant after four people died on the state's roads on Sunday, taking the long-weekend road toll to nine.
No deaths have been recorded in the ACT.
A 52-year-old male driver was fined by members of the Goulburn Highway Patrol on Sunday for driving at 173km/h in a 110km/h zone, police said.
A police spokesman said officers saw the vehicle speeding at 6.25pm and issued the driver with infringement notices for exceeding the speed limit by more than 45km/h and not carrying a licence.
He received a six-month suspension notice and had his registration plates seized, the spokesman said.
A single-vehicle crash claimed three lives on Sunday, after the vehicle left the roadway and rolled near Narrabri.
Acting Traffic and Highway Patrol operations commander, Acting Superintendent Mark Cook, said motorists should heed the warnings to show caution.
“Nine people have died on our roads in three days, which is way too many," he said.
“I find it really concerning that based on our most recent statistics, 3538 people have been caught speeding since Friday, compared to 2864 during the comparable period last year."