In 2013, the National Transportation Safety Board (NTSB) proposed lowering the blood alcohol content to 0.05 to cut down the risk of DWI accidents. Mothers Against Drunk Driving (MADD), the minds behind DWI law in the U.S., welcomes the development. The recommended BAC, however, still remains at 0.08.
The BAC limit used to be much higher. Back then people hadn't heard much of the dangers and consequences of "driving under the influence." Only a few studies delved into the cognitive effects of alcohol. Indiana took the lead by imposing a 0.15 presumptive limit in 1939; 16 years later, Minnesota followed.