Driver's License Test Prep
California Practice DUI & Impaired Driving

You are driving a vehicle that requires a commercial driver's license. What is the commercial-driver BAC limit for a DUI charge in California?

  1. A.
    0.04% Correct
  2. B.
    0.01%
  3. C.
    0.08%
The Why

The answer is "0.04%"

The commercial threshold is 0.04% or higher, half the 0.08% adult figure. Choice C tempts drivers who carry the 0.08% number over from personal driving, missing that a vehicle requiring a CDL is held to the stricter line.

Why the others miss

The traps in the wrong answers

B. 0.01%

0.01% is the threshold for drivers under 21, and for drivers of any age on DUI probation, not the commercial-driver line. This answer grabs the smallest number in the BAC list and reads it as the commercial line because it sits next to the CDL entry in the manual.

C. 0.08%

0.08% is the general adult limit for personal driving; the commercial-driver line is stricter. This answer carries the 0.08% figure quoted everywhere for personal driving over to a CDL vehicle without noticing the stricter commercial line.

The Rule

This question tests your knowledge of DUI & Impaired Driving in California. Source: California Driver Manual, "Blood Alcohol Concentration (BAC) Limits," p.73..

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