Final answer:
Zero tolerance laws set a strict BAC limit for underage drivers, which is separate from the general BAC limit of 0.08% for of-age drivers. These laws aim to prevent underage drinking and driving, influenced by the National Minimum Drinking Age Act and advocacy groups like MADD.
Step-by-step explanation:
In the United States, zero tolerance laws are aimed at preventing underage drinking and driving. These regulations prohibit drivers under the age of 21 from operating a vehicle with any detectable level of alcohol in their bloodstream. The National Minimum Drinking Age Act of 1984 influenced states to adopt the minimum legal drinking age of 21, and established penalties for states that did not comply, including a reduction in federal highway funds. Mothers Against Dru nk Driving (MADD) played a significant role in advocating for this legislation.
For most drivers, a BAC of 0.08% or higher is considered legally dru nk in many states. However, for minors, the zero tolerance laws enforce a much lower BAC limit, typically between 0.00% and 0.02%, to discourage drinking and driving entirely among young people and to promote safer roadways.
The zero tolerance laws do not reduce the BAC limit from 0.08%; instead, they establish a separate and much stricter BAC threshold specifically for underage drivers.