I believe the new blood alcohol limitations are a waste of time and a fig leaf to really dealing with the abuse of alcohol and driving.
The report below (which is from 2003, I've been unable to find more recent figures) shows those with blood alcohol between 50 and 80 to be just 5% of fatal accidents. And those with no alcohol at all in their systems were 30%, another 20% were not tested.
while those over 160 mg/ml are involved in nearly 30% of fatal accidents.
The numbers involved in accidents who are between 50mg and 80mg would not indicate that this is the area that needs most attention. A more sensible approach would be punish more severely based on the degree to which you are over the limit. We should do the same with speeding and link fines to a % of income.
What are we doing about the bigger problem of those who are completely ignoring the existing limits and effectively driving while hammered? The answer is - nothing.