Skip to content

Alcohol, Other Drugs, and Driving

Alcohol, Other Drugs, and Driving is addressed through 49 CFR 383.111(a)(1)(v) (the effects of alcohol and drug use on safe commercial motor vehicle operations). Two rules tested here are directly codified: 49 CFR 392.5’s 4-hour pre-duty and on-duty zero-tolerance rules, and 49 CFR 392.4’s prohibition on operating under the influence of a controlled substance.

Practice Alcohol, Other Drugs, and Driving

5 Questions

  1. How long before going on duty or operating a commercial motor vehicle must a driver avoid using alcohol or being under its influence?
  2. What is the federal rule on alcohol use while a driver is on duty, operating, or in physical control of a commercial motor vehicle, separate from the 4-hour pre-duty rule?
  3. Which of the following is prohibited for a driver who is on duty, under 49 CFR 392.4?
  4. When does the federal drug prohibition NOT apply to a driver taking medication?
  5. If a driver becomes too ill to drive safely, what is the correct response?