Washington CDL — General Knowledge practice
Washington CDL — General Knowledge: Alcohol & Drugs practice test
Blood alcohol limits, zero-tolerance and implied-consent laws, and how alcohol and drugs — legal or not — affect your driving.
Content reviewed against official driver handbooks · August 12, 2026
14 questions · pass with 11 correct. You get instant feedback and an explanation after every answer.
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12 sample Alcohol & Drugs questions with the correct answer, a short explanation, and the official handbook reference. Read through them, then take the quiz above.
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1. By operating a commercial motor vehicle, what have you agreed to regarding alcohol testing?
Correct answer: You have consented to alcohol testing
If you operate a CMV, you are deemed to have given your consent to alcohol testing.
Source: Washington CDL Guide — Section 1: Introduction (CDL Disqualifications)
2. After drinking, what is the only thing that will actually reduce the alcohol in your body?
Correct answer: Only the passage of time
Only time will sober you up; the liver removes alcohol at a fixed rate, and black coffee or a cold shower will not speed it up.
Source: Washington CDL Guide — Section 2: Driving Safely (How Alcohol Works)
3. What is the safest rule regarding drugs and driving?
Correct answer: Do not mix drugs with driving at all
The safest rule is not to mix any drugs with driving at all, because alcohol can also make the effects of other drugs much worse.
Source: Washington CDL Guide — Section 2: Driving Safely (Other Drugs)
4. For a first offense of driving a CMV with a BAC of .04% or higher, how long will you lose your CDL?
Correct answer: At least one year
A first alcohol offense costs you your CDL for at least one year.
Source: Washington CDL Guide — Section 1: Introduction (CDL Disqualifications)
5. What is the penalty for using a commercial motor vehicle to commit a felony involving controlled substances?
Correct answer: Loss of your CDL for life
Using a CMV to commit a felony involving controlled substances means losing your CDL for life.
Source: Washington CDL Guide — Section 1: Introduction (CDL Disqualifications)
6. About how much alcohol can the liver process in one hour?
Correct answer: About one-third of an ounce per hour
The liver can only process about one-third of an ounce of alcohol per hour, which is less than the alcohol in a standard drink.
Source: Washington CDL Guide — Section 2: Driving Safely (How Alcohol Works)
7. At what blood alcohol concentration is it illegal to operate a commercial motor vehicle?
Correct answer: .04% or more
It is illegal to operate a CMV with a blood alcohol concentration of .04% or more.
Source: Washington CDL Guide — Section 1: Introduction (CDL Disqualifications)
8. What happens if you are found to have any detectable amount of alcohol below .04% while operating a CMV?
Correct answer: You are put out of service for 24 hours
Any detectable amount of alcohol under .04% will put you out of service for 24 hours.
Source: Washington CDL Guide — Section 1: Introduction (CDL Disqualifications)
9. What is the penalty for a second major offense such as driving a CMV under the influence?
Correct answer: Loss of your CDL for life
A second major offense results in the loss of your CDL for life.
Source: Washington CDL Guide — Section 1: Introduction (CDL Disqualifications)
10. Why should a commercial driver be cautious about common over-the-counter cold medicines?
Correct answer: They can make you drowsy and affect your driving
Cold medicines and other over-the-counter drugs can make a driver drowsy or otherwise affect safe driving ability.
Source: Washington CDL Guide — Section 2: Driving Safely (Other Drugs)
11. How long will you lose your CDL for a first alcohol offense committed while operating a CMV placarded for hazardous materials?
Correct answer: At least three years
If the offense occurs while operating a placarded hazmat vehicle, the disqualification is at least three years.
Source: Washington CDL Guide — Section 1: Introduction (CDL Disqualifications)
12. When is it permitted to drive after taking a prescription drug your doctor gave you?
Correct answer: Only if the doctor says it will not affect safe driving
Use of a drug prescribed by a doctor is permitted if the doctor informs you it will not affect your safe driving ability.
Source: Washington CDL Guide — Section 2: Driving Safely (Other Drugs)
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Every Washington question is written from the official Washington driver handbook and checked against its current edition. DMV Test Free is a free, independent study resource — not affiliated with any DMV or government agency. About DMV Test Free