Alcohol, Drugs, and Driver Fitness
Alcohol, Drugs, and Driver Fitness tests the CMV alcohol limit, disqualification rules, drug and medication issues, and medical fitness requirements.
Core rules
- The CMV alcohol limit is 0.04 BAC; the non-commercial 0.08 limit does not apply to CMV operation.
- Do not drive within 4 hours of drinking alcohol.
- Refusing an alcohol test triggers disqualification. A first alcohol violation generally means a 1-year disqualification; a hazmat violation means 3 years; a second violation means lifetime disqualification.
- Marijuana remains illegal under federal rules, and prescription or over-the-counter drugs can impair driving.
- Maintain a valid DOT medical examiner’s certificate and meet vision and hearing standards.
- Report convictions and license suspensions to your employer as required.
Worked example
A driver blows 0.05 in a CMV. Even though 0.08 is the non-commercial threshold, 0.04 applies to CMVs, so the driver is over the limit and faces out-of-service and disqualification.
Traps
Using 0.08 as the CMV limit; assuming prescription medicine is always safe; not reporting a DUI; driving too soon after drinking.