Final answer:
The legal BAC limit for drivers 21 and older in the majority of U.S. states is 0.08%. This limit is part of efforts to prevent alcohol-impaired driving. Organizations like MADD have significantly contributed to the establishment of stricter drinking laws, such as the National Minimum Drinking Age Act of 1984.
Step-by-step explanation:
The legal Blood Alcohol Concentration (BAC) limit for drivers aged 21 and older in the United States is 0.08%. This level is set to discourage driving under the influence and is upheld in most states. Driving with a BAC at or above this limit can lead to arrest and charges for driving under the influence (DUI) or driving while intoxicated (DWI). It is important to remember that alcohol metabolism varies among individuals, and the safest option is to not drive after drinking at all.
Given the body's metabolism rate of alcohol, even if drinking stops, it takes at least five hours for a legally intoxicated person to achieve sobriety. Meanwhile, MADD has been a key player in establishing laws aiming to reduce alcohol-impaired driving, which includes pushing for the enactment of the National Minimum Drinking Age Act of 1984. This act mandated states to set the drinking age at 21 or risk losing federal highway funds.