Assessing fitness to drive in a young man with type 1 diabetes

A young man, John, who has just completed an engineering degree and who you have only seen a few times before comes to see you because his private class C driver’s licence is due for renewal. He is 24 years old, lives with his girlfriend and has had type 1 diabetes for 12 years. You have no pathology results available for him but he says he has been under the care annually of an endocrinologist. He has had no regular doctor as he ‘doesn’t get sick’. He has no other medical problems.