Posted By Andrew Meiklejohn Andy I have come across this one in the past and I think you're right there are no limits mentioned for dui, unless you are on public roads in which case its 80mg/100ml. However at 50-80mg/ml there is Impaired judgement of distances. Impaired adaptability of eyes to changing light conditions. Impaired sensitivity to red lights. Severe impairment of ability to react and of concentration. Even at 20-50mg/ml there is an Inability to see or locate moving lights correctly. Problems in judging distances and a tendency to take risks. So IMO the zero/zero approach is justifiable, and in my opinion should be enforced as long as you have the appropriate support.