Alcohol, Drugs, and Driver Fitness
This domain tests alcohol and drug limits, implied consent, and medical fitness for CDL drivers.
Alcohol
The CDL limit is 0.04% BAC in Minnesota; the non-commercial DWI limit is 0.08%. Refusing a test triggers implied-consent revocation. A CDL driver with any alcohol in the vehicle may be placed out of service.
Drugs
Marijuana remains prohibited for CDL drivers under federal rules, even where state law allows recreational use. Prescription and over-the-counter medications must not impair driving; check with a doctor.
Fitness
Keep a current DOT medical certificate; most drivers need a physical every 24 months. Self-certify your driving category. Report medical changes that affect driving.
Worked example
A CDL driver blows 0.05% BAC. Reasoning: 0.05 is above the 0.04 CDL limit, so the driver is over the limit even though below 0.08. The driver is out of service and subject to DWI/implied-consent consequences.
Traps that cost marks
Thinking 0.08 applies to CDLs; using CBD products that may contain THC; letting a medical certificate expire.