What is the current legal BAC limit for driving in the US and Canada?

• A. 0.10%.
• B. 0.08%.
• C. 0.00%.
• D. 0.05%.

Answer: (B)

The main idea here is the standard threshold at which driving with alcohol is considered legally impaired in both the US and Canada. That commonly used limit is eight hundredths of a percent BAC.

This value is chosen because research shows that at about this level, alcohol reliably impairs driving-related skills—slower reactions, poorer judgment, and reduced coordination—which corresponds to a higher crash risk. Lawmakers set this point as the general benchmark for impairment, triggering legal penalties for driving after drinking.

There are some context-specific differences you’ll encounter in practice. For example, commercial drivers often face a stricter limit, and Canada uses the same general standard while allowing for additional penalties at lower levels in certain circumstances. But for the typical driving impairment baseline, the eight hundredths of a percent BAC is the standard reference.