Lots of very interesting answers, thanks. As one who has had a fil, a mother and a father- who all drove way beyond the time when they should have given up their car- I realise how hard it is to give up driving- especially for those in more remote areas and without public transport.
My mum had 2 minor accidents, only damage to the car and a lamp-post- and gave in her licence. She had been driving for 80 years and was previously a brilliant driver.
Dad waited much longer, but again, gave up when he drove into a railway crossing and wrote his car out. Actually no, he got another car- too powerful and changed to automatic- and 'frit' himself and sold it. Thank goodness they both stopped before run over a child. They both said 'oh but we only drive locally' - but a child can cross the road a few feet from your house! As for my fil, he had his licence removed twice, then still continued to drive, least said. Again, thank goodness nothing happened. He gave up after his 3rd heart attack.
My post however was related to those British expats living in Italy, France or Spain- often in very rural areas- who are now unable to swap their driving licences as required for non EU residents. Many have done the right thing, sent their licences to be swapped, which were returned with 'no need' - and now find it impossible, either because they are over 70, or licence has expired in meantime, etc.
In France, if they have to retake, they will have to do so in French, including the theory course and the first aid course. And even if they are good, safe drivers- I'd say this would be very daunting for many. Can you imagine?