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DMV Permit · General

At what blood alcohol concentration (BAC) does the law typically consider a commercial driver legally impaired?

Correct answer

0.04% — commercial drivers (CDL holders) are held to a stricter standard because they operate larger, more dangerous vehicles and drive professionally

  1. A 0.08% (same as non-commercial drivers)
  2. B 0.04% — commercial drivers (CDL holders) are held to a stricter standard because they operate larger, more dangerous vehicles and drive professionally
  3. C 0.10%
  4. D 0.02%

Why this is the answer

COMMERCIAL DRIVER ALCOHOL LIMITS: BAC 0.04% is the legal limit for CDL holders operating commercial vehicles — half the standard adult limit of 0.08%. WHY STRICTER: Commercial vehicles weigh up to 80,000 lbs; stopping distances are much longer; the consequences of crashes are more severe; commercial drivers are professionals who have accepted greater responsibility. PRACTICAL IMPLICATIONS: A commercial driver who had two drinks with dinner and registers 0.04% BAC is legally DUI while driving their commercial vehicle — even though the same BAC is below the legal limit for their personal vehicle. This standard applies any time the CDL holder is operating a commercial vehicle. CDL DUI CONSEQUENCES: 1-year disqualification for first offense; lifetime disqualification for second offense or any offense in a CMV.
Source: DMV Handbook, Commercial Driver BAC Limit

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