One in 10 motorists over 70 are not fit to be on the road, according to a leading research charity.
The RAC Foundation has released a report called 'Driving Choices for the Older Motorist', which claims some older drivers are stopping before they need to, while others remain a hazard.
The report says of the 500,000 drivers turning 70 this year, 50,000 will be unfit to drive.
There are currently 3.9m drivers over the age of 70 on the road in the UK who have to self-certify that they are fit to drive when they reach 70 and every three years after, but there is no formal medical assessment required.
The numbers are set to increase dramatically too, according to government projections – researchers predict that of all UK citizens alive today, 10m will reach 100.
RAC Foundation director, Professor Stephen Glaister, said: "In general older drivers have an enviable safety record but it is clear that faced with this critical yes or no decision many motorists simply do not have a realistic view of their capabilities."
"While this will mean there are drivers who are unfit to be on the roads there will be many others who have prematurely hung up their keys. This will have a huge impact on their ability to live an active life, access essential services and take part in social activities."
Glaister added that he doesn't support compulsory retesting of older drivers, but over-70s need to be better educated on how to assess their abilities.