Eight adults and two children were the latest casualties in road accidents in Australia from Friday night 'til after midnight Monday, prompting the police to call on the public to make sure that everyone wears seatbelts when travelling.

On Friday night, a 24-year-old man and two children died when their car crashed into a tree south of Jandowae, Queensland.

On Saturday afternoon, an 81-year-old woman died after a head-on collision at Caboolture north of Brisbane. The other car from the collision only had one passenger, the driver, who sustained minor injuries.

In Victoria on Saturday night, three people were killed in separate road accidents. Two men believed to be in their 50s died at Shepherd's Flat north of Ballart and in Wallan north of Melbourne when they each seemed to have lost control of their vehicles, and they were taken on the wrong side of the road, with one crashing into a guard rail and the other, into a tree.

The third Victoria casualty, a 20-year-old man, died after he had been run over at Wandin North.

In West Australia, another man died in a car crash on the Mitchell Freeway north of Perth also on Saturday night.

On Sunday morning, about 5:30 am, a man was killed when his car crashed at Dalveen, south of Warwick.

On Monday just after midnight, a 34-year-old man died when his vehicle crashed at Pikedale, west of Stanthorpe on Queensland's southern border.

The separate fatal accidents prompted the police authorities to urge car drivers and passengers to always wear their seatbelts when on the road. They did not identify the passenger victims who did not have their seatbelts on, but said the number of deaths could have been smaller if all of them took a simple safety precaution on the road.

"The simple act of wearing a seatbelt can increase your chances of surviving a traffic crash, no matter how long or short the journey," Inspector Ray Rohweder told ABC News.