All states agreed in 2004 to carry a “minimum-maximum” standard of .08 BAC per se, not overriding more severe measure. With this standard, anyone driving with a BAC greater than .08 would be subject to criminal charges, generally a DUI (Driving While Under the Influence).
Reaching this mark is highly variable and extremely difficult to determine, as an “impairment” of .08 does not effect all equally For a 140lb male, this equates to ~3 12oz. beers in an hour.
