DUI Laws in California

This article provides a comprehensive overview of DUI laws in California, detailing the legal framework, penalties, and procedures involved.

Driving Under the Influence (DUI) is a serious offense in California, governed by stringent laws and regulations. This article provides a comprehensive overview of DUI laws in California, detailing the legal framework, penalties, and procedures involved. It aims to offer a thorough understanding of the subject, focusing on legitimate sources such as government websites and official legal documents.


Driving under the influence of alcohol or drugs is a significant public safety issue. California has implemented strict DUI laws to deter impaired driving and protect its citizens. This article delves into the specifics of these laws, including the legal definitions, penalties, and the legal process involved in DUI cases.

California Vehicle Code Section 23152

California Vehicle Code Section 23152 is the primary statute governing DUI offenses. It defines the act of driving under the influence and sets forth the legal thresholds for blood alcohol concentration (BAC).

Subsection (a): Alcohol Impairment

Under Section 23152(a), it is unlawful for a person to drive a vehicle if they are under the influence of alcohol. This subsection does not specify a BAC limit but focuses on the impairment of the driver.

Subsection (b): BAC Limit

Section 23152(b) makes it illegal to drive with a BAC of 0.08% or higher. This is the per se limit, meaning that driving with this BAC level is automatically considered a DUI offense, regardless of actual impairment.

Subsection (f): Drug Impairment

Section 23152(f) addresses driving under the influence of drugs. It is illegal to drive a vehicle while impaired by any drug, including prescription medications and illegal substances.

Subsection (g): Combined Influence

Section 23152(g) covers cases where a driver is under the combined influence of alcohol and drugs. This subsection ensures that drivers who are impaired by multiple substances are held accountable.

California law sets different BAC limits for various categories of drivers:

  • Standard Drivers: 0.08%
  • Commercial Drivers: 0.04%
  • Drivers Under 21: 0.01%

These limits reflect the increased responsibility and reduced tolerance for impairment among commercial drivers and minors.

Penalties for DUI Offenses

First Offense

A first-time DUI offense in California carries several penalties, including:

  • Fines: Up to $1,000, plus additional penalty assessments.
  • License Suspension: Six months, with the possibility of obtaining a restricted license.
  • DUI School: Mandatory attendance at a DUI education program.
  • Probation: Informal probation for three to five years.
  • Jail Time: Up to six months, though this is often waived in favor of probation and community service.

Second Offense

A second DUI offense within ten years results in harsher penalties:

  • Fines: Up to $1,000, plus penalty assessments.
  • License Suspension: Two years, with the possibility of a restricted license after one year.
  • DUI School: Extended DUI education program.
  • Probation: Informal probation for three to five years.
  • Jail Time: 96 hours to one year.

Third Offense

A third DUI offense within ten years leads to even more severe consequences:

  • Fines: Up to $1,000, plus penalty assessments.
  • License Suspension: Three years, with the possibility of a restricted license after 18 months.
  • DUI School: 30-month DUI education program.
  • Probation: Informal probation for three to five years.
  • Jail Time: 120 days to one year.

Fourth and Subsequent Offenses

A fourth DUI offense within ten years is considered a felony:

  • Fines: Up to $1,000, plus penalty assessments.
  • License Revocation: Four years, with the possibility of a restricted license after two years.
  • DUI School: 30-month DUI education program.
  • Probation: Formal probation.
  • Prison Time: 16 months to three years.

Aggravating Factors

Certain factors can enhance the penalties for a DUI offense, including:

  • High BAC: A BAC of 0.15% or higher.
  • Refusal to Submit to Testing: Refusing a chemical test can result in additional penalties.
  • Accidents: Causing an accident while driving under the influence.
  • Minor Passenger: Having a minor in the vehicle at the time of the offense.

DUI Process in California

Arrest and Booking

The DUI process begins with the arrest and booking of the suspect. Law enforcement officers will conduct field sobriety tests and chemical tests to determine impairment.


The arraignment is the first court appearance, where the defendant is formally charged and enters a plea. The court will also set bail and schedule future court dates.

Pretrial Motions

Pretrial motions may include requests to suppress evidence, dismiss charges, or compel discovery. These motions are crucial in shaping the defense strategy.

Plea Bargaining

Many DUI cases are resolved through plea bargaining, where the defendant agrees to plead guilty to a lesser charge in exchange for reduced penalties.


If the case goes to trial, both the prosecution and defense will present evidence and arguments. The judge or jury will then determine the defendant's guilt or innocence.


If the defendant is found guilty, the court will impose a sentence based on the severity of the offense and any aggravating factors.

Administrative Penalties

Administrative Per Se (APS) Suspension

The Department of Motor Vehicles (DMV) imposes an Administrative Per Se (APS) suspension for drivers who fail or refuse a chemical test. This suspension is separate from any criminal penalties and can be contested through a DMV hearing.

Ignition Interlock Device (IID)

An Ignition Interlock Device (IID) may be required for certain DUI offenders. This device prevents the vehicle from starting if the driver has a measurable amount of alcohol in their system.

DUI and Minors

Zero Tolerance Law

California's Zero Tolerance Law prohibits drivers under 21 from operating a vehicle with a BAC of 0.01% or higher. Violating this law results in a one-year license suspension and mandatory DUI education.

Underage DUI Penalties

Underage DUI offenders face additional penalties, including fines, community service, and mandatory attendance at a DUI education program.

DUI and Commercial Drivers

Lower BAC Limit

Commercial drivers are subject to a lower BAC limit of 0.04%. Violating this limit can result in a one-year disqualification from operating a commercial vehicle.

Enhanced Penalties

Commercial drivers face enhanced penalties for DUI offenses, including longer license suspensions and mandatory participation in a substance abuse program.

DUI and Drugs

Prescription Medications

Driving under the influence of prescription medications is illegal if the medication impairs the driver's ability to operate a vehicle safely. Drivers must be aware of the potential side effects of their medications.

Illegal Substances

Driving under the influence of illegal substances, such as marijuana or cocaine, is strictly prohibited. Penalties for drug-related DUI offenses are similar to those for alcohol-related offenses.

Defenses to DUI Charges

Invalid Stop

One common defense is that the traffic stop was invalid. Law enforcement officers must have reasonable suspicion to stop a vehicle. If the stop was unlawful, any evidence obtained may be suppressed.

Faulty Testing Procedures

Another defense is that the testing procedures were faulty. This can include issues with the calibration of the breathalyzer or errors in the administration of field sobriety tests.

Rising BAC

The rising BAC defense argues that the defendant's BAC was below the legal limit while driving but increased to an illegal level by the time the test was administered.

Medical Conditions

Certain medical conditions, such as acid reflux or diabetes, can affect BAC readings. A skilled attorney can present evidence of these conditions to challenge the accuracy of the test results.


California's DUI laws are designed to protect public safety by deterring impaired driving. Understanding these laws, the penalties involved, and the legal process is crucial for anyone facing a DUI charge. By adhering to the legal limits and avoiding impaired driving, individuals can contribute to safer roads and communities.

For more information on California DUI laws, please refer to the following official resources:

By staying informed and making responsible choices, drivers can help reduce the incidence of DUI-related accidents and fatalities in California.

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