Agree with Jopar.....I just got notified by DVLA (after a hypo incident whilst driving) that I will be able to keep driving.,,,,,my advice is this:
DVLA's advice that they sent out to me today was:
''Do not drive if you feeel hyp or if your BG is less than 4.0''
Later in literature they say:
''If glucose is 5 or less take a snack before driving''
I cannot emphasis enough how important it is to be safe to self and others whilst driving. The DVLA do not automatically revoke driving licences, and yes, they do have to be renewed every 3 years. Please, please ensure that your son NEVER takes any risks, and that he ALWAYS does a BG before driving.
It is automatic that T1's are issued 3 year licences. I cannot over emphasis to be honest and truthful in completing forms. The DVLA people have been excellent with me, but I have had a battle with GP's, Consultants, even writing to my MP and under enormous pressure after a stupid, needless incident whilst driving.
The DVLA do take a time to correspond, and it will probably be 100 days before you get a response, but providing your son's Medical Persons say he is safe to continue to drive then, he should. HOWEVER, please, please get him to have a meter in his car always (mine is under my handbrake, so a great reminder before driving off) and get him ALWAYS to test before he drives...just like clunk click.....don't drive if below 5.......