Virginia CDL — General Knowledge practice
Virginia 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
12 questions · pass with 10 correct. You get instant feedback and an explanation after every answer.
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.
Show all 12 questions with answers
1. When may a driver use a prescription drug given by a doctor while driving a CMV?
Correct answer: If the doctor says it will not affect safe driving ability
A physician-prescribed drug is allowed if the doctor advises that it will not impair the driver's ability to operate safely.
Source: Virginia CDL Manual — Section 2: Driving Safely (Other Drugs)
2. What is the only real cure for fatigue behind the wheel?
Correct answer: Rest or sleep
No drug or trick substitutes for rest; the only genuine cure for fatigue is sleep, so do not use anything that merely hides tiredness.
Source: Virginia CDL Manual — Section 2: Driving Safely (Driver Fatigue)
3. About how much alcohol can the liver process in an hour?
Correct answer: Roughly one-third of an ounce
The liver clears only about a third of an ounce of alcohol per hour, less than one standard drink, and only time will lower your BAC.
Source: Virginia CDL Manual — Section 2: Driving Safely (How Alcohol Works)
4. As blood alcohol rises, which ability is impaired first?
Correct answer: Judgment and self-control
Alcohol first affects judgment and self-control, which can keep a drinker from realizing how impaired they are becoming.
Source: Virginia CDL Manual — Section 2: Driving Safely (Alcohol and the Brain)
5. What is the only thing that will sober up a person who has been drinking?
Correct answer: Time
Because the liver removes alcohol at a fixed rate, only the passage of time, not coffee or a shower, will sober you up.
Source: Virginia CDL Manual — Section 2: Driving Safely (How Alcohol Works)
6. Which factors determine a person's blood alcohol concentration?
Correct answer: How much you drink, how fast, and your body weight
BAC depends on the amount of alcohol consumed, how quickly it is consumed, and the drinker's weight.
Source: Virginia CDL Manual — Section 2: Driving Safely (What Determines BAC?)
7. Refusing to take a blood alcohol test while operating a CMV brings what first-offense penalty?
Correct answer: Loss of the CDL for at least one year
Refusing testing is treated like the other major alcohol offenses: at least a one-year disqualification for a first offense.
Source: Virginia CDL Manual — Section 1: Introduction (Disqualifications)
8. 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 5% beer
A 12-ounce beer, a 5-ounce glass of wine, and a 1.5-ounce shot of liquor all hold roughly the same amount of alcohol.
Source: Virginia CDL Manual — Section 2: Driving Safely (What Is a Drink?)
9. Why does a smaller person generally reach a given BAC on less alcohol than a larger person?
Correct answer: There is less body mass for the alcohol to spread through
With less body weight, the same amount of alcohol produces a higher concentration, so a small person does not have to drink as much.
Source: Virginia CDL Manual — Section 2: Driving Safely (What Determines BAC?)
10. What does alcohol do to the effects of other drugs?
Correct answer: Can make them much worse
Alcohol can greatly intensify the effects of other drugs, so the safest rule is to keep drugs and driving completely separate.
Source: Virginia CDL Manual — Section 2: Driving Safely (Other Drugs)
11. By operating a commercial vehicle, a driver is considered to have agreed to what?
Correct answer: Alcohol testing
Driving a CMV means you have given implied consent to alcohol testing.
Source: Virginia CDL Manual — Section 1: Introduction (Disqualifications — Alcohol)
12. Why can ordinary over-the-counter cold medicine be a concern before driving?
Correct answer: It can make you drowsy and affect safe driving
Many cold and other non-prescription medicines can cause drowsiness or otherwise impair driving, so heed their warning labels.
Source: Virginia CDL Manual — Section 2: Driving Safely (Other Drugs)
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