The national holiday road toll has climbed to 31 on the first day of the year.
A 40-year-old Kingscote man died on Friday after a car rollover on South Australia's Kangaroo Island, his death taking the state's holiday road toll to three.
A motorcyclist died in Nunawading, in Melbourne's east, after he lost control and veered into a tree just after 8.30pm.
Their deaths on New Year's Day bring the national holiday road toll to 31.
Ten people have died in New South Wales, eight in Victoria and five in Queensland over the 2015 festive season.
Two people have been killed in the ACT, while Western Australia, Tasmania and the Northern Territory have recorded one fatality each.
A 25-year-old man was arrested on Friday over the single NT death - an alleged fatal hit-and-run in Darwin on New Year's Eve.
Police say the pedestrian, a 37-year-old man, was hit about 10.30pm at Ludmilla by a speeding car that did not stop.
A second person who was in the car is also being questioned, and police are urging another man to come forward as they continue investigations.
"In particular we'd like to speak with a 23-year-old male by the first name of Dylan, who we believe was the third occupant of the vehicle," Detective Senior Sergeant Tony Henrys said.
Queensland, Victoria and South Australia also recorded New Year's Eve fatalities.
A 31-year-old man died after his motorcycle collided with a car at Slacks Creek in Logan, near Brisbane, about 6.30pm and a 19-year-old was killed when a car driven by a learner rolled at Mt Mercer in Victoria's west about 8pm.
In South Australia, a man died shortly after his car hit a tree on the South-Eastern Freeway in Monarto South at 3.30pm on Thursday.
* The national road toll period runs from 0001 December 23, 2015, until 2359 January 3, 2016, local times.
