the problem with that is that you can be over the limit, without having consumed any alcohol.[medication can do this]
so that is not a good idea.,it is a litle unfair to lose your licence if you have not consumed alcohol ,do you not think?
no[imo],bad driving, carelessness, driving while using a mobile phone and excessive speed is more of a problem.
I had a driver hit the side of my house,she was perfectly sober,but lost contol on a bend cos she was driving far too fast.