This is alot like another thread on here right now! In alanon we learn not to avoid a crisis, but not to create one either. At this point it sounds to me like it would be creating a crisis so that you would feel better. If the consequences of his addiction occur naturally, and you are not involved, then you and he both cannot "blame" you. I'm sure I could call the cops on my daughter today, send them out to the opiate den she is living in, but that would be me creating a crisis, and I am working on detaching. He will have consequences, probably not as quickly as you would like. If no one is at risk of being harmed I would let it go. As far as driving goes, if you are positive he is impaired, that might be a bottom line for me, a time to make a call to the police.