Driving under the influence — California Permit Test
Driving under the influence on the California permit test — 6 rules, each with the reason behind it and a question on it while it is fresh.
The rules
California’s driving under the influence laws apply to both alcohol and drugs, and it is illegal to drive while under the influence of alcohol or any drug that affects your ability to drive safely.
What matters is whether you can still drive, not what it was that stopped you.
California’s driving under the influence (DUI) laws apply to both alcohol and drugs.
The law does not see a difference between illegal drugs and medications you get from a doctor or pharmacy, because they can all affect your ability to drive safely and react to what you see and hear.
A prescription makes a drug legal to take. It does not make you safe to drive on it.
The law does not see a difference between illegal drugs and medications you get from a doctor or pharmacy.
As you age, your tolerance to alcohol decreases, which increases the risk of alcohol-related driving problems.
The same drink that did little at twenty does more at sixty, and the limit has not moved.
As you age, your tolerance to alcohol decreases, which increases the risk of alcohol-related driving problems.
It is illegal to drive after drinking excessive amounts of alcohol in any form, including medications like cough syrup.
A dose of cough syrup is a dose of alcohol, and the breath test does not care where it came from.
Drinking excessive amounts of alcohol in any form. This includes medications like cough syrup.
If a law enforcement officer thinks you are driving under the influence of drugs or alcohol, they have the right to ask you to take a blood or urine test, and refusing means DMV will suspend or revoke your driving privilege for one year.
Refusing does not avoid the penalty. It brings a different one that lasts a year.
If you refuse to take one, DMV will suspend or revoke your driving privilege for one year.
If you are 13 to 20 years old and convicted of operating a bicycle while under the influence of alcohol or drugs, your driving privilege may be suspended or delayed for one year once you are eligible to drive.
A bicycle conviction reaches forward and takes the license you have not got yet.
IMPORTANT: If you are 13 to 20 years old and convicted of operating a bicycle while under the influence of alcohol or drugs, your driving privilege may be suspended or delayed for one year once you are eligible to drive.
On the test
What do California’s DUI laws cover?
Alcohol and drugs alike. What matters is whether you can still drive, not what it was that stopped you. California Driver’s Handbook, p.72: “California’s driving under the influence (DUI) laws apply to both alcohol and drugs.”
How this works
Most practice tests hand you a bank of questions and leave the manual somewhere else. This one puts them together.
You read one law and the reason behind it, then answer a question on that law while it is still fresh. Get it right and you move on; get it wrong and you have found the gap while it is cheap to fix, not on the morning of the exam.
Learning one rule at a time, and proving it immediately, is what turns a manual you skimmed into something you actually know — and it makes studying feel like getting somewhere rather than like waiting to find out.
What it costs
- One payment, once — not a subscription. Nothing renews and there is nothing to cancel, for an exam you sit one time.
- Free to start: a 10-question test and the first section of cards. No sign-up and no account.
- Paying opens the rest of the cards, unlimited full-length practice tests, and retests built from exactly the questions you got wrong.
- Every level up to Prepared — 3 tests passed in a row.
- Do the work, fail the real exam, and we refund you.
Where these come from
Every rule here is checked against California Driver’s Handbook, published by the California Department of Motor Vehicles, and against the state code itself. Last checked 2026-09-21.
- src/assets/drivers-manuals/CA.pdf (California Driver’s Handbook, DL 600 ENGLISH (REV. 6/2025), retrieved 2026-09-14; sha256 pinned in SOURCES.json)
- src/assets/drivers-manuals/CA.pages.txt (the pdftotext -layout fixture every citation here was cut against and verified against; sha256 pinned in SOURCES.json)
- src/assets/drivers-manuals/SOURCES.json, CA entry — the folio offset of 6 and its basis, the three non-law pages, the two sign gallery pages, and the record of why California’s exam shape is this app’s own
- docs/plans/chosen-exam-shapes.md section 5 — the decision that a state publishing neither exam figure ships 40/32 with both disclosed
- docs/plans/how-to-build-laws.md — the rule that the handbook is the syllabus and nothing enters this file without a page in it