In California, drivers age 21 and older are presumed to be DUI with BAC of at least what percent?

In California, drivers age 21 and older are presumed to be DUI with BAC of at least what percent?

• A. .10%
• B. .05%
• C. .08%
• D. .12%

Answer: (C)

The main idea is the legal limit used to define DUI for adult drivers. In California, if a driver aged 21 or older has a blood alcohol concentration of 0.08 percent or higher, the law treats that as DUI per se, meaning impairment is presumed and prosecutors can convict based on the BAC alone. This threshold is used because it reflects a level at which driving impairment becomes reliably risky, providing a clear enforcement standard. If the BAC is below 0.08, a DUI charge can still be possible if there is other evidence the driver is impaired, such as field sobriety test results or erratic driving. There are different limits for other groups: commercial drivers have a 0.04% limit, and drivers under 21 face a much lower limit (0.01%), reflecting stricter rules for minors. So, for age 21 and older, the BAC threshold is 0.08%.

The main idea is the legal limit used to define DUI for adult drivers. In California, if a driver aged 21 or older has a blood alcohol concentration of 0.08 percent or higher, the law treats that as DUI per se, meaning impairment is presumed and prosecutors can convict based on the BAC alone. This threshold is used because it reflects a level at which driving impairment becomes reliably risky, providing a clear enforcement standard. If the BAC is below 0.08, a DUI charge can still be possible if there is other evidence the driver is impaired, such as field sobriety test results or erratic driving. There are different limits for other groups: commercial drivers have a 0.04% limit, and drivers under 21 face a much lower limit (0.01%), reflecting stricter rules for minors. So, for age 21 and older, the BAC threshold is 0.08%.