Drive Safe Online Practice Exam

What is the typical legal BAC limit for drivers aged 21 and over in most states?

0.05 percent BAC 0.00 percent BAC 0.08 percent BAC 0.10 percent BAC

Correct Answer:

0.08 percent BAC

Explanation:

For adult drivers, the law uses a per se limit: if your BAC is at or above 0.08%, you’re considered legally impaired to drive. This 0.08% threshold is the standard adopted by most states for drivers aged 21 and over, making it illegal to operate a vehicle once that level is reached or exceeded, based on a breath or blood test. Impairment can begin at lower levels, and some situations or categories (like commercial drivers or underage drivers) use different limits, but 0.08% is the typical standard for adults 21 and over. The other options are less representative of the common rule: 0.05% is used in some contexts or states, 0.00% would imply zero tolerance that isn’t the general rule for adults, and 0.10% is higher than the standard in most places.

Access more questions from this quiz

Continue to Drive Safe Online Practice Exam for more practice questions and the full quiz experience.

Access More Questions