The national holiday road toll has climbed to 27 with New Year’s Eve fatalities in Victoria and South Australia.

A young man died when a car he was a passenger in rolled at Mt Mercer in Victoria’s west about 8pm on Thursday.

In South Australia, a man died shortly after his car hit a tree on the South-Eastern Freeway in Monarto South at 3.30pm.

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His death takes the state’s holiday season toll to two, while Victoria’s now stands at seven. Ten people have died on NSW roads this holiday period.

The Northern Territory is the only state or territory not to have recorded any road deaths.

*The national road toll period runs from 0001 December 23, 2015 until 2359 January 3, 2016, local times.