Alcohol, Drugs & Distracted Driving in California
Impaired and distracted driving are leading causes of fatal crashes in California. The state has strict DUI laws and near-zero tolerance for driving under the influence — understanding the legal limits and consequences is required for your DMV knowledge test.
Blood Alcohol Content (BAC) Limits
The legal BAC limit for drivers 21 and older is 0.08%. For commercial drivers, the limit is 0.04%. For drivers under 21, California has a zero tolerance law — a BAC of 0.01% or higher results in license suspension. For drivers on DUI probation, any measurable alcohol (0.01%) is a violation. A BAC of 0.16% or higher typically results in enhanced penalties.
DUI Consequences
A first DUI offense typically results in license suspension, fines, DUI school enrollment, and possible jail time. Refusing a chemical test (breath, blood, or urine) after a lawful arrest results in an automatic license suspension — longer than if you had taken the test. California's implied consent law means you've already agreed to a chemical test by driving on California roads.
Distracted Driving
California prohibits holding or using a handheld phone or any electronic device while driving. Hands-free use (mounted device, Bluetooth) is permitted for drivers 18 and over. Drivers under 18 may not use any wireless device, even hands-free. Eating, applying makeup, or any other activity that takes attention from the road is also considered distracted driving.
Key Rules at a Glance
- Legal BAC limit (21+): 0.08%
- Commercial driver BAC limit: 0.04%
- Under 21 BAC limit: 0.01% — zero tolerance
- Refusing chemical test: Automatic license suspension (longer than DUI suspension)
- Handheld phone while driving: Prohibited — hands-free only for 18+
- Under 18 — wireless devices: No use at all, even hands-free