Prince Philip has been declared “unhurt” after overturning his Land Rover while driving to the royal Sandringham estate on Friday.

But while the Duke of Edinburgh’s – just five months shy of his 98th birthday – narrowly avoided injury, the incident  has prompted fresh debate about the safety of older drivers.

Should Prince Philip still be able to get behind the wheel? Is there a threshold age when driving is no longer safe?

The car the Duke was driving overturned in the collision. Photo: KLFM

President of British motoring body the Automobile Association Edmund King said many commentators used high-profile crashes to call for bans or restrictions on older drivers.

Mr King, also a well known transport commentator, said if driving restrictions based on age and safety were introduced, younger drivers would in fact be more likely to be restricted than older drivers.

“The decision to hang up your keys is a tough one, but it should be based on personal advice from your GP and family rather than being based on some arbitrary age,” Mr King said.

Is there an age to call it quits?

British motorists are required to renew their licence at 70 years old, and every subsequent three years thereafter.

Prince Philip has a drivers licence and would be no exception to this rule, while his wife, Queen Elizabeth II does not require a licence because all licences are issued in her name.

Similar age-based rules exist around the world, with slight variations in each state and territory in Australia.

Prince Philip has a drivers licence at 97-years-old. Photo: Getty

Driving authorities in New South Wales and Queensland require drivers at the age of 75 to have a medical review every year to keep a drivers licence.

But transport accident researchers say there’s no cut-off age for driving.

Professor Barry Watson, from the Centre for Accident Research and Road Safety at the Queensland University of Technology, told The New Daily there was no age when driving becomes less safe.

Prince Philip waves while being driven in a royal motorcade. Photo: Getty

“What influences safety is not chronological age but how medically fit they are to drive and that can vary widely from person to person,” Professor Watson said.

He said vision could deteriorate from the age of 40 and the risk of being involved in a road crash only increased slightly until the age of 75.

“And even at that point it’s still a lower [risk] than it is for younger drivers,” Professor Watson said.

“The highest crash risk is young people very new to driving, or young people who have just got their provisional licence, in that first six to 12 months of driving.”

Ageism directed at older drivers

Given there is “no firm or good evidence” to suggest driving authorities should stop older people from driving, Professor Watson said some older drivers felt discriminated against.

The Council on the Ageing in Australia (COTA) is among groups which say driving restrictions should only apply to medical conditions.

“We oppose automatic age-based cut-off because people’s capacities vary so enormously,” COTA chief executive Ian Yates told The New Daily.

“There are people that shouldn’t be driving in their 40s and 50s and people in their 80s that have never had an accident or incident in their life,” he said.

Mr Yates said current policies in Australia were “ageist” and a non-aged-based alternative should be sought in the same way 65-year-olds are no longer required to retire.

“There were many people who lost their jobs when there was a compulsory retirement age, and we fought for years to get rid of that,” he said.