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Alcohol and Drugs — California Driver's License Practice Test

Alcohol and DrugsQuestion 1 of 30

31 questions in this topic · 30 drawn at random this round

What device may a DUI conviction require you to install in your vehicle?

CA Driver Handbook

All questions are based on the official California Driver Handbook. Study the relevant section to reinforce your knowledge.

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This California Driver's License Alcohol and Drugs practice set has 31 practice questions based on the official exam materials, each with an instant explanation. You need 83% on the real California Driver's License knowledge test to pass.

Topic overview

This chapter covers the legal limits for driving under the influence, the fact that alcohol, illegal drugs, prescription medications, and even over-the-counter drugs and cough syrup are all treated the same way under the law, and California's implied consent rule for chemical testing.

The most-tested concepts are the different BAC (blood alcohol concentration) thresholds that apply to different drivers — general adult drivers are held to a less strict standard than commercial and for-hire drivers, and drivers under 21 or on DUI probation face a zero-tolerance standard. Also expect questions on open-container rules for both alcohol and cannabis, and on the consequences of a DUI conviction or refusing a chemical test.

A common mistake is assuming "prescription" or "legal" drugs are exempt from DUI law — they are not; any substance that impairs your ability to drive safely counts. Another is forgetting that refusing a chemical test carries its own separate license penalty, independent of any DUI conviction.

Does it matter if the drug that impaired me was legally prescribed?

No — the law makes no distinction between illegal drugs and medications from a doctor or pharmacy. If a substance affects your ability to drive safely, driving under its influence is illegal.

Why are the BAC limits different for different types of drivers?

California sets a stricter (lower) limit for drivers who are under 21, on DUI probation, or driving commercially or for hire, because of the added responsibility or heightened risk in those situations — always check which category applies to you.

What happens if I refuse a chemical test after being lawfully arrested for DUI?

Under California's implied consent law, refusing a breath, blood, or urine test after a lawful DUI arrest results in its own license suspension or revocation — separate from whatever happens with the DUI charge itself.

Written from the official California Driver Handbook — Alcohol and Drugs ↗· Last checked: 2026-07-10· Reviewed by the PassPrep editorial team· How we verify →

Sample questions

Three questions from the Alcohol and Drugs bank with the correct answer and an explanation. The practice quiz above draws 30 questions at random from the same bank.

Which of the following is illegal in California?
- Driving while under the influence of alcohol or any drug that affects safe driving — Correct answer
- Driving after a full night of sleep
- Driving with a passenger in the front seat
- Driving with the windows down
Explanation: It is illegal to drive while under the influence of alcohol or any drug that affects your ability to drive safely.
Handbook: Alcohol and Drugs — Driving Under the Influence
At what blood alcohol concentration (BAC) is a driver 21 or older considered to be driving under the influence?
- 0.08% or higher — Correct answer
- 0.01% or higher
- 0.04% or higher
- 0.10% or higher
Explanation: A driver 21 or older is driving under the influence at a blood alcohol concentration of 0.08% or higher.
Handbook: Alcohol and Drugs — BAC Limits
At what blood alcohol concentration (BAC) is a driver under 21 in violation of the law?
- 0.01% or higher — Correct answer
- 0.08% or higher
- 0.04% or higher
- 0.05% or higher
Explanation: A driver under 21 is in violation at a blood alcohol concentration of 0.01% or higher.
Handbook: Alcohol and Drugs — Drivers Under 21