DUI, or Driving Under the Influence, means driving with alcohol or substances in your system. As a result, you’re found to violate the law. In California, it’s illegal for someone to drive while under the influence of alcohol or drugs or with a blood alcohol concentration of 0.08% or more.
For commercial drivers, there are stricter requirements. Commercial drivers can be arrested for a DUI if they have a blood alcohol concentration of 0.04% or more.