Deaths on Australian roads have increased by 7.2 per cent in the 12 months to the end of September – with 1273 fatalities recorded, a four-year high – and authorities are at a loss as to how to end the carnage.

However, a study released by the Australasian New Car Assessment Program (ANCAP), a non-profit authority that monitors the crash worthiness of cars, has unearthed some startling statistics.

The safety body found the oldest vehicles (built 1999 or earlier) account for 20 per cent of cars on the road – but were involved in 36 per cent of fatalities.

Conversely, new vehicles (built between 2010 and 2015) account for 31 per cent of the fleet – but were involved in 11 per cent of fatalities.

South Australia has the oldest car fleet in mainland Australia, with vehicles built before 2000 making up 26 per cent of those on the road.

In another disturbing finding, the report revealed that, although the average age of all cars on Australian roads is 9.8 years, the average age of vehicles involved in fatal crashes was 12.5 years. The average age of South Australia’s vehicle fleet is 11.4 years.

Meanwhile, Federal Government data shows drivers aged 40 to 64 have had the largest spike in road deaths in the past 12 months (up by a staggering 18.2 per cent), while deaths of novice drivers (17 to 25) dropped by 3.2 per cent over the same period.

The deaths of older drivers also rose across other age brackets over the previous 12 months. Road fatalities of those aged 65 to 74 were up 12.4 per cent, and those aged 75 and older were up 13 per cent.

So far this year in South Australia, 21 of the 76 road deaths have been people aged 70 or over. The latest findings have renewed calls by experts for buyers to consider newer, safer cars.

“Of course not everyone can afford a brand-new car; however, the figures show that there is less chance of being killed in a newer and safer car than an older and less safe vehicle,” ANCAP boss James Goodwin said.

“This research highlights the stark reality of what’s happening on our roads and could go some way to explaining why the road toll is rising.”

Goodwin added: “There needs to be a renewed focus on vehicle safety to reduce the road toll, including more regular safety checks of older vehicles.”

Most states and territories across Australia, including SA, currently do not require annual safety checks of older vehicles, leaving it up to car owners – and police – to look out for defects such as bald tyres and worn brakes.