Alcohol & Drugs

Study questions with answers

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.

1. 1. How does alcohol affect a driver's abilities?

   Correct answer: It impairs coordination, reaction time, and judgment

   Alcohol dulls coordination, slows reaction time, and weakens depth perception and night vision, while clouding the judgment that safe driving requires.

   Source: North Carolina CDL Driver Handbook — Section 2: Driving Safely (2.22.1)

2. 2. About how fast can the liver process alcohol?

   Correct answer: About one-third of an ounce of alcohol per hour

   The liver can process only about one-third of an ounce of alcohol per hour — less than a standard drink — and only time will sober you up.

   Source: North Carolina CDL Driver Handbook — Section 2: Driving Safely (2.22.1)

3. 3. Under the rules, which over-the-counter medicines can be a problem for a commercial driver?

   Correct answer: Common cold medicines that can cause drowsiness

   Cold medicines and similar over-the-counter drugs can make a driver drowsy and impair safe driving, so drivers must pay attention to warning labels.

   Source: North Carolina CDL Driver Handbook — Section 2: Driving Safely (2.22.2)

4. 4. At what blood alcohol concentration does it become illegal to operate a commercial motor vehicle?

   Correct answer: .04 percent

   It is illegal to drive a CMV with a blood alcohol concentration of .04 percent or more — a lower limit than for non-commercial drivers.

   Source: North Carolina CDL Driver Handbook — Section 1: Introduction (1.3.2)

5. 5. Which of these contains about the same amount of alcohol as a 1.5-ounce shot of 80-proof liquor?

   Correct answer: A 12-ounce glass of ordinary beer

   A regular 12-ounce beer, a 5-ounce serving of wine, and a single 1.5-ounce shot of 80-proof liquor each hold about the same amount of alcohol.

   Source: North Carolina CDL Driver Handbook — Section 2: Driving Safely (2.22.1)

6. 6. If a first alcohol offense occurs while you are driving a CMV placarded for hazardous materials, how long will you lose your CDL?

   Correct answer: Three years

   The disqualification is at least three years if the offense happens while operating a vehicle placarded for hazardous materials, rather than the usual one year.

   Source: North Carolina CDL Driver Handbook — Section 1: Introduction (1.3.2)

7. 7. What is the penalty for a second major alcohol- or drug-related offense involving a CMV?

   Correct answer: Loss of the CDL for life

   A second major offense of this kind means losing the CDL permanently; the same lifetime loss applies to anyone who uses a commercial vehicle in a felony tied to controlled substances.

   Source: North Carolina CDL Driver Handbook — Section 1: Introduction (1.3.2)

8. 8. For at least how long do you lose your CDL the first time you refuse a required alcohol test while operating a CMV?

   Correct answer: At least one year

   Refusing to undergo blood alcohol testing while operating a CMV results in loss of your CDL for at least one year on a first offense.

   Source: North Carolina CDL Driver Handbook — Section 1: Introduction (1.3.2)

9. 9. Which method will actually reduce a person's blood alcohol concentration?

   Correct answer: Letting enough time pass

   Only the passage of time lowers BAC; black coffee, a cold shower, or fresh air do not speed up how fast the body removes alcohol.

   Source: North Carolina CDL Driver Handbook — Section 2: Driving Safely (2.22.1)

10. 10. What happens if you are found operating a CMV with a detectable amount of alcohol below .04 percent?

    Correct answer: You are placed out of service for 24 hours

    Any detectable amount of alcohol under .04 percent puts you out of service for 24 hours.

    Source: North Carolina CDL Driver Handbook — Section 1: Introduction (1.3.2)

11. 11. Which part of the brain does alcohol affect first as blood alcohol concentration rises?

    Correct answer: The part controlling judgment and self-control

    Alcohol first affects the part of the brain that controls judgment and self-control, which is dangerous because it can keep drinkers from realizing they are impaired.

    Source: North Carolina CDL Driver Handbook — Section 2: Driving Safely (2.22.1)

12. 12. When is it permitted to drive after taking a prescription drug?

    Correct answer: Only if the doctor says it will not affect safe driving

    You may drive after taking a drug prescribed by a doctor only if the doctor has told you it will not affect your ability to drive safely.

    Source: North Carolina CDL Driver Handbook — Section 2: Driving Safely (2.22.2)