indeed , as you say a lot of people including my mum continue to drive way past the point where they are safe on the road and im not just talking about speed but the awareness of the surroundings for whatever reason be it cognitive or sight related .
it took a stroke and the dvla telling her she couldn’t drive before she gave up , before then she was having lots of little "accidents " but was unwilling to stop.
My Grandad liked to go for drives out into North Wales
He was saying one day that he had been going through one of the tunnels on the North Wales coast road and was not sure whether his headlights were working or not
he got out but had to go right up to the lights and actually put his eye against the lens to see if it was working or not
IT WAS!!
My Dad was rather alarmed and persuaded him to stop driving soon after
Only the Gods know how long he had been driving basically unable to see much at all
he was a wonderful driver, careful, calm and experienced - but not being able to see would certainly override all that!!!
These people are out there!!