What are the major offenses that disqualify a CDL driver under 49 CFR 383.51?

Short answer

The major offenses that disqualify a CDL driver under 49 CFR 383.51 include being under the influence of alcohol or a controlled substance, having an alcohol concentration of 0.04 or greater while operating a CMV, and refusing to take an alcohol test.

1. Being under the influence of alcohol as prescribed by State law

2. Being under the influence of a controlled substance

3. Having an alcohol concentration of 0.04 or greater while operating a CMV

4. Refusing to take an alcohol test as required by a State or jurisdiction under its implied consent laws or regulations.

The rule says

"Being under the influence of alcohol as prescribed by State law" (49 CFR 383.51(b)(1))

"Being under the influence of a controlled substance" (49 CFR 383.51(b)(2))

"Having an alcohol concentration of 0.04 or greater while operating a CMV" (49 CFR 383.51(b)(3))

"Refusing to take an alcohol test as required by a State or jurisdiction under its implied consent laws or regulations" (49 CFR 383.51(b)(4))

In plain English

These major offenses can result in a CDL driver being disqualified from operating a commercial motor vehicle for a period of time, ranging from 1 year to a lifetime, depending on the offense and whether it is a first or subsequent conviction. The disqualification periods are designed to protect public safety by removing drivers who have demonstrated risky behavior from the roads. Employers must also comply with these regulations by not allowing a disqualified driver to operate a CMV.

What to do

• Review the driver's record to determine if they have been convicted of a major offense.
• Check the applicable disqualification period based on the offense and the driver's history.
• Remove the driver from CMV operation if they are disqualified.
• Notify the driver and maintain documentation of the disqualification and any subsequent actions taken.