Radio businesses have not been hit as hard by digital disruption as traditional print and television for a simple reason - the cars Australians drive are old.

The average registered vehicle in the country was made more than a decade ago, and this has made it difficult for radio listeners to switch to new digital formats, Citi analyst David Kaynes says.

Older cars without the ability to connect smartphones could be the reason why radio has remained resilient as other media companies struggle with digital disruption.

While consumers can stop buying newspapers and switch to online formats, and televisions and accessories are regularly upgraded, people are slower to buy new cars.

The average age of all motor vehicles registered in Australia was 10.1 years in January 2017, a figure that has remained stable for years, according to Australian Bureau of Statistics data.