Driver's License Test Prep
California Practice DUI & Impaired Driving

You are 19 years old and driving in California. At what blood alcohol concentration (BAC) or higher can you be charged with DUI?

  1. A.
    0.00%
  2. B.
    0.08%
  3. C.
    0.01% Correct
The Why

The answer is "0.01%"

For drivers under 21, California sets the DUI threshold at 0.01% BAC. Choice A comes from reading 'zero tolerance' literally, but the manual prints 0.01% because trace readings from mouthwash or medicine can register on a breath test.

Why the others miss

The traps in the wrong answers

A. 0.00%

The under-21 threshold is 0.01%, not literal zero. This answer reads 'zero tolerance' as an actual zero reading, ignoring that the printed figure leaves room for trace exposures.

B. 0.08%

0.08% is the adult limit; under-21 drivers face a stricter cutoff. This answer carries the adult figure into the under-21 line because drivers see 0.08% quoted most often in public messaging.

The Rule

This question tests your knowledge of DUI & Impaired Driving in California. Source: California Driver Manual, "Blood Alcohol Concentration (BAC) Limits," p.73..

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