The argument is that BAC isn't a valid way to measure anything pertinent. It doesn't show how drunk you are, or how impaired you are, it just shows how much alc

The argument is that BAC isn't a valid way to measure anything pertinent. It doesn't show how drunk you are, or how impaired you are, it just shows how much alcohol is in your blood. It sounds like a good measurement, except that alcohol affects everyone differently (both physically and mentally). One person could have a BAC of .03 and be unable to walk. Another person could have a BAC of .12 before they get wobbly. There are too many factors in play (weight, tolerance, metabolism, hydration, food, etc) to make the measurement meaningful in regard to driving ability.