Good post! Clears up one or two questions I had, but I am still confused by
about 1 unit, or twice the limit imposed by the act
When you say "1 unit" do you mean the classic "UK unit = 120ml wine/half pint of beer"?
I hope not because what you would be implying is that there is a standard relationship between what you throw down your neck and what is evidenced in breath or blood. And there isnt - and it could mislead a lot of people, especially women, oriental races, etc. (see earlier posts).
Apologies if I have misconstrued what you have said.
Pinkman