It's a sad fact that many elderly drivers refuse to accept that they're no longer fit to drive, when in truth they know it all along.
Before you all scream at me, I'm sure that I'll also feel that way one day and not want to lose my freedom voluntarily.
One member here this year has said that they realised that their driving days are now over and I take my hat off to them, I hope I will be the same, but the chances are that we'll all refuse to see the obvious when it's in front of us.
What's needed is bi-annual competence checks at age 65-75 and then annual checks, not driving tests, checks on reflexes, sight and the like to check your ability to carry on driving safely, and they should be carried out independently at a DVLA nominated medical centre that doesn't allow your own GP to test you. The results should be available to insurers, and then I'm sure most drivers will retire from driving voluntarily by the cost of insurance premiums that would be reflected by the results of their check.
At present a Doctor has to notify DVLA that a driver is not fit to drive if they fall into compulsory notification classes, but are reluctant to do so other than that. This way every one would have to pass regular age related competence checks without their personal GP feeling guilty if they fail you.