Driving under the influence is a crime even if your blood alcohol content was below the legal limit as long as the alcohol affected your ability to drive. If your BAC is a .05 or below and you are over 21 and not a commercial driver, you are presumed innocent of DUI, but if it is below 0.08%, but above 0.06%, then the case will largely rely on the police officer’s testimony, including how you fared on the Field Sobriety Tests -if you agreed to take these optional tests.
Any drivers under the age of 21 are subject to California’s zero-tolerance DUI law, meaning they can get a DUI for driving with a BAC over 0.01%. Those with commercial licenses cannot drive with a BAC over 0.04% at any time, while those who are drivers for hire (for companies such as Lyft) cannot have a BAC above 0.04% while on the clock.