The families of people with dementia are being urged to encourage their loved ones to give up driving, because of the potential dangers including the threat to their own lives, and those of others on the roads.
Alzheimer's Disease affects 800,000 people in this country, and before diagnosis and even after - some sufferers are still driving when they should not be behind the wheel.
A survey by a road safety charity has found a decline in the cognitive abilities of older motorists was the biggest worry for more than half of those questioned.
When David Orr from South Oxfordshire was diagnosed with Alzheimers, his family convinced him to stop driving. He has said that although it was a hard conversation to have, he is glad his relatives were honest with him. He told his story to our reporter Kate Bunkall.