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. Which abilities does alcohol impair that are critical to safe driving?

   Correct answer: Coordination, reaction time, depth perception, and night vision

   Alcohol impairs muscle coordination, reaction time, depth perception, and night vision, and it weakens judgment.

   Source: Indiana CDL Manual, Section 2 (Alcohol and Driving)

2. 2. Common over-the-counter cold medicines can affect a commercial driver in what way?

   Correct answer: They can make you drowsy and unsafe to drive

   Cold medicines and similar drugs may make you drowsy or otherwise reduce your ability to drive safely, so heed their warning labels.

   Source: Indiana CDL Manual, Section 2 (Other Drugs)

3. 3. Roughly how much alcohol can the liver process in one hour?

   Correct answer: About one-third of an ounce

   The liver clears only about one-third of an ounce of alcohol per hour, a fixed rate that means only time will make you sober.

   Source: Indiana CDL Manual, Section 2 (Alcohol and Driving)

4. 4. What kinds of driving errors are commonly caused by alcohol impairment?

   Correct answer: Weaving, straddling lanes, and running stop signs

   Alcohol leads to errors such as straddling lanes, weaving, jerky starts, failing to signal, and running stop signs and red lights.

   Source: Indiana CDL Manual, Section 2 (Alcohol and the Brain)

5. 5. It is illegal to operate a commercial motor vehicle when your blood alcohol concentration reaches what level?

   Correct answer: .04%

   Operating a CMV with a BAC of .04% or more is against the law and leads to loss of your CDL.

   Source: Indiana CDL Manual, Section 1 (Alcohol, Leaving the Scene, and Felony)

6. 6. If a commercial driver has any detectable amount of alcohol below .04%, what happens?

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

   Any detectable amount of alcohol under .04% results in being placed out of service for 24 hours.

   Source: Indiana CDL Manual, Section 1 (Alcohol, Leaving the Scene, and Felony)

7. 7. Why should a driver never use drugs to mask fatigue?

   Correct answer: They keep you awake but not alert, and rest is the only cure

   Drugs may keep you awake for a while but will not make you truly alert, and the only real cure for fatigue is rest.

   Source: Indiana CDL Manual, Section 2 (Other Drugs)

8. 8. Three factors determine your blood alcohol concentration. Which set is correct?

   Correct answer: How much you drink, how fast you drink, and your weight

   BAC depends on how much alcohol you drink, how quickly you drink it, and your body weight.

   Source: Indiana CDL Manual, Section 2 (What Determines BAC?)

9. 9. Which is true about the amount of alcohol in a 12-ounce beer, a 5-ounce glass of wine, and a 1.5-ounce shot of 80-proof liquor?

   Correct answer: They all contain the same amount of alcohol

   All three standard drinks contain the same amount of alcohol, so it makes no difference which one you consume.

   Source: Indiana CDL Manual, Section 2 (What Is a Drink?)

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

    Correct answer: The part governing judgment and self-control

    Alcohol first affects judgment and self-control, which can keep drinkers from realizing they are becoming impaired.

    Source: Indiana CDL Manual, Section 2 (Alcohol and the Brain)

11. 11. Under the rules, when may a driver use a prescription drug supplied by a doctor while on duty?

    Correct answer: Only if the physician says it will not impair safe driving

    You may use a doctor-prescribed drug only if the physician tells you it will not affect your ability to drive safely.

    Source: Indiana CDL Manual, Section 2 (Other Drugs)

12. 12. By operating a CMV, a driver is deemed to have given consent to what?

    Correct answer: Alcohol testing

    Driving a CMV means you have given implied consent to alcohol testing.

    Source: Indiana CDL Manual, Section 1 (Alcohol, Leaving the Scene, and Felony)