By the ChowChow Labs editorial team · Updated November 6, 2026 · How we check our content
Alcohol and driving
Legal rule
Alcohol slows judgment before you feel drunk. Only time sobers you up; coffee and cold air don't. For drivers under 21, California has zero tolerance for alcohol. If you've been drinking, arrange another ride.
Example: After a party a friend offers coffee 'so you're fine to drive.' You book a ride home instead.
Check the official wording in the California Driver Handbook.
Medicines can impair you
Legal rule
Driving impaired is illegal whether the drug is illegal, prescribed or bought over the counter. Read warning labels and don't drive if a medicine makes you drowsy or dizzy.
Example: A cold tablet says it may cause drowsiness. You take it after you get home, not before your drive.
Check the official wording in the California Driver Handbook.
Phones and other distractions
Legal rule
Holding a phone while driving is not allowed in California. Drivers under 18 may not use a phone at all, even hands-free. Set navigation before you leave, and pull over safely for anything that takes your eyes or hands off driving.
Example: A long text arrives on the freeway. You leave it until you can stop at a rest area.
Check the official wording in the California Driver Handbook.
Drowsy driving
Safety recommendation
Yawning, heavy eyelids and drifting in your lane are signs you need rest. Loud music and open windows only help briefly. Stop somewhere safe and rest.
Example: On an overnight drive you miss your exit sign. You pull into the next rest stop for a nap.
Check the official wording in the California Driver Handbook.
Check yourself
Try these 5 questions from our free mock exams, then tap Show answer. For more, take the rules of the road practice test.
Question 1 · Alcohol, Drugs and Distraction
You keep yawning and missing road signs on a long drive. What should you do?
- A. Open the window and turn up the music, then keep going until your next planned stop.
- B. Leave the road at a safe spot and take a real break or nap before driving on.
- C. Turn up music as a substitute for rest.
- D. Drive faster to finish sooner.
Show answer
Answer: B. Leave the road at a safe spot and take a real break or nap before driving on.
Drowsiness slows reactions and can cause brief micro-sleeps. Cold air, music or caffeine only mask it for a moment; real rest is the fix.
Question 2 · Alcohol, Drugs and Distraction
A prescription makes you dizzy before you plan to drive. What should you do?
- A. Use coffee to cancel impairment.
- B. Drive anyway, since a medicine your doctor prescribed can't lead to a DUI.
- C. Assume a prescription prevents a DUI.
- D. Do not drive while impaired; check warnings and arrange another way to travel.
Show answer
Answer: D. Do not drive while impaired; check warnings and arrange another way to travel.
Legal medicines can impair driving. The source of a substance does not make impaired driving safe.
Question 3 · Alcohol, Drugs and Distraction
After drinking, you feel confident but notice slower reactions. What should you do?
- A. Drink a strong coffee and wait twenty minutes, then drive home carefully and slowly.
- B. Drive slowly as a substitute for sobriety.
- C. Assume feeling confident proves fitness.
- D. Arrange a sober ride and do not drive if affected by alcohol.
Show answer
Answer: D. Arrange a sober ride and do not drive if affected by alcohol.
Alcohol can affect judgment before a person recognizes the impairment; a low reading does not establish safe driving.
Question 4 · Alcohol, Drugs and Distraction
A long message arrives while you are driving. How should you handle it?
- A. Pull over safely before handling a distracting task.
- B. Hold the phone below the window.
- C. Let the car ahead guide you while typing.
- D. Read it quickly while traffic is moving slowly, then put the phone down.
Show answer
Answer: A. Pull over safely before handling a distracting task.
A phone task can take attention and hands away from driving. Stop safely before interacting when the task would distract you.
Question 5 · Alcohol, Drugs and Distraction
Which of these is an early sign that you're too tired to drive?
- A. Feeling a little hungry.
- B. Wanting to change the radio station.
- C. Drifting out of your lane or missing your exit.
- D. Noticing more road signs and details than you usually would.
Show answer
Answer: C. Drifting out of your lane or missing your exit.
Lane drifting, heavy eyelids and missed turns mean it's time to stop and rest.
Next: Permits and Test Preparation. Practicing with a minor's permit, supervised hours and test day.