UPDATE: THE national holiday road toll has reached 22, with the latest victim dying in a two car crash in Adelaide this afternoon.

NSW has the highest state road toll with seven deaths, while six people have died in Victoria.

Four people have died on Western Australia's roads and three people in South Australia, with police in Queensland and Tasmania reporting one person killed in each state.

Only the Northern Territory and the ACT remain fatality-free at this stage.

Earlier today a driver was  killed after his car veered into the path of an oncoming truck and burst into flames in Victoria's west.

Victoria Police said the collision happened on a straight stretch of the Princes Highway at Warncoort, near Colac, just before 7am.

An Ambulance Victoria spokesman said the service was called at 6.48am.

He said the car was on fire and the driver of the vehicle died at the scene.

A truck driver, believed to be in his 40s, was uninjured and wasn't taken to hospital.

The death brings the national road toll to 20.

Anyone with information is urged to contact Crime Stoppers on 1800 333 000 or visit www.crimestoppers.com.au.

Last night, a man and a woman have died after their motorcycle crashed with a car in Western Australia.

The 47-year-old male rider and 39-year-old female passenger died after their motorcycle collided with a Jeep in Bullsbrook, north of Perth, about 7.40pm yesterday.

Both died at the scene, while the driver of the Jeep and a passenger were uninjured.