A recent study published in the Journal of Studies on Alcohol and Drugs shows that designated drivers might not be so "designated" after all, and in fact could be at risk of DUI charges, even if buzzed. In other words, these drivers may not be performing their supposed function - that is: driving drunken friends and partygoers around while remaining sober behind the wheel - as often as you'd like to believe.
The study, as Michelle Castillo reports for CBS News, shows that 40 percent of designated drivers have some amount to drink before driving. They're not necessarily drinking to excess, but just one, two, or three drinks can put someone over the 0.05 threshold (the threshold proposed recently by the federal National Transportation Safety Board) for blood alcohol content.
It doesn't take much, in fact, to get someone over the 0.08 limit, which is the national standard at the moment, and has been for many years.
One or two drinks can create that buzzed feeling, as Professor Adam Berry describes it. But he also says that being buzzed is not a good yardstick for measuring amount of impairment. Castillo quotes Berry: "People do try to use that as a measuring stick. But alcohol is insidious ... We should not trust a designated driver to be sober."
In Arizona, you can get nabbed for impaired driving even if you're not over the 0.08 limit. The law allows for the police to arrest you for DUI even if you're buzzed - like many designated drivers, apparently - or otherwise shown not to be able to operate a car safely.