Coming into this discussion a bit late, but as with some of the others - in my view, lowering the limit is pretty pointless. Have a look at the figures from any random breath testing campaign. Two points stand out - one is that the vast majority of those over the limit are well over. And that the proportion of those tested actually above the limit is actually very small, usually way under 1%; compare the figures for drivers involved in fatal accidents - 20-30% are above the limit, again, the vast majority well above.
As a non-drinker, I obviously have little concern what the limit is, although it need to be borne in mind that if set too low, accidental ingestion can cause you to exceed the limit - and if zero is ever enshrined in law, remember that the minimum detectable is continually getting lower!
John
