California DUI Law & Commercial Driver's Licenses
Vehicle Code 23152(d) and 15300 VC

California driving under the influence (“DUI”) laws are particularly harsh to holders of commercial driver's licenses, in two ways.

First, under California Vehicle Code 23152(d) VC, if you are driving a commercial vehicle, you are guilty of DUI if a chemical breath test or blood test shows that you have a blood alcohol concentration (“BAC”) of .04% or above1 (not the .08% limit that applies to drivers of non-commercial vehicles).2

Second, if you hold a commercial driver's license and are convicted of any form of DUI (including Vehicle Code 23152(a) VC driving under the influence or Vehicle Code 23152(b) VC driving with a BAC of .08 or greater), your right to drive a commercial vehicle will be suspended for a period of at least one (1) year.3

This is true even if you were not driving a commercial vehicle at the time of your offense.4

In contrast, even though defendants convicted of California DUI will also receive non-commercial driver's license suspensions for at least six (6) months, these defendants can usually get restricted licenses during the suspension period. Restricted licenses allow them to drive to and from work and California DUI school.5

Vehicle Code 23152(d) VC reads: "(d) It is unlawful for a person who has 0.04 percent or more, by weight, of alcohol in his or her blood to drive a commercial motor vehicle, as defined in Section 15210. In any prosecution under this subdivision, it is a rebuttable presumption that the person had 0.04 percent or more, by weight, of alcohol in his or her blood at the time of driving the vehicle if the person had 0.04 percent or more, by weight, of alcohol in his or her blood at the time of the performance of a chemical test within three hours after the driving."


  • Paul is a big-rig driver. He is passing through the town where his childhood friend Steve lives. Steve and Paul meet up for a few drinks. Then Paul gets into his truck, Steve gets into his car, and they both drive away. A few minutes later they both hit a DUI sobriety checkpoint. Steve has a BAC of 0.06 and is not considered to be DUI. But Paul has a BAC of 0.05 and is arrested for DUI pursuant to Vehicle Code 23152(d) VC.
Truck drivers need to be aware of the particular DUI laws that apply to commercial drivers, such as VC 23512(d) and 15300.

Legal defenses

As you can see from the above example, California's DUI law for commercial license holders can be incredibly unfair—and have devastating professional consequences.

If you are a commercial driver charged with DUI under VC 23152(d) or another California DUI law, an experienced California DUI defense lawyer can help you fight the charges using certain common DUI defenses, such as:

  • Your DUI chemical test results were inaccurate; or
  • Police did not use proper procedures when they stopped or arrested you.

In order to help you better understand California DUI laws and penalties as they apply to commercial drivers, including Vehicle Code 23152(d) VC, our California DUI defense attorneys will address the following:

If, after reading this article, you would like more information, we invite you to contact us at Shouse Law Group.

1. How Do California DUI Laws Like VC 23152(d) Apply to Commercial Drivers?

Under Vehicle Code 23152 VC, you can violate California DUI laws while driving a commercial vehicle by doing any of the following:

  1. Driving the commercial vehicle under the influence of any alcoholic beverage (meaning that your mental or physical abilities are so impaired that you are no longer able to drive with the caution of a sober person using ordinary care6);
  2. Driving the commercial vehicle with a blood alcohol concentration (“BAC”) of 0.04 percent or higher (this is the special form of commercial vehicle DUI set forth in VC 23152(d));
  3. Driving the commercial vehicle under the influence of any drug, or under the combined influence of alcohol and any drug (this is what is known as “VC 23152(f) DUI of drugs”);7
  4. Driving the commercial vehicle while under the influence of alcohol, or with a BAC of 0.04 or higher, and at the same time doing an unlawful or negligent act that proximately causes bodily injury to someone else (this is what is known as “DUI causing injury”);8 or
  5. Refusing to submit to a California DUI chemical test when that test is required by law (also known as a “chemical test refusal”).9

Essentially, DUI for commercial drivers is the same as DUI for drivers of non-commercial vehicles—with the exception that under Vehicle Code 23152(d) VC you are automatically considered to be DUI if you have a BAC of 0.04 or higher.

The legal limit for commercial drivers is a BAC of 0.04 under Vehicle Code 23512(d) VC, whereas for other drivers it is a BAC of 0.08.

Note that it will be presumed that you drove with a BAC of 0.04 or higher if a chemical test measures your BAC at 0.04 or higher within three (3) hours after driving—although this presumption may be rebutted.10

Example: Carol is a school bus driver. At the end of a particularly hard day, she takes a few swigs from a flask of whiskey after she drops off her last student. Then she drives the empty bus back to the lot.

A bystander sees Carol drink from the flask and calls the police, giving them the license plate number of the bus. Police meet Carol at the lot where she drops off the bus and arrest her.

Carol is taken to the police station and given a DUI chemical blood test there. It shows her BAC to be just over 0.04 percent approximately an hour after she parked the school bus.

Carol can be charged with commercial vehicle DUI based on these facts.

Definition of a commercial vehicle

If you're wondering what a “commercial vehicle” is for purposes of California commercial-driver DUI law, it includes all of the following:

  1. A double trailer;
  2. A passenger vehicle that carries more than ten (10) persons including the driver;
  3. A school bus;
  4. A tank vehicle; or
  5. A vehicle that carries hazardous substances and requires a placard.11

Commercial vehicles do not, however, include:

  • Recreational vehicles (RVs); or
  • Agricultural vehicles operated by people who are not required to obtain driver's licenses in California.12

2. What are the Penalties for California DUI If I Hold a Commercial License?

Commercial driver's license holders need to be especially concerned about California DUI penalties under laws like VC 23152(d)—even if they were not driving a commercial vehicle when they committed a DUI.

2.1. What are the basic penalties for DUI in California?

Regardless of whether you were driving a commercial or non-commercial vehicle at the time of your DUI, if this is your first, second or third DUI conviction, you will likely face the following California misdemeanor penalties:

  • Informal DUI probation;
  • Up to one (1) year in county jail;
  • Between three hundred ninety dollars ($390) and one thousand dollars ($1,000) in fines; and/or
  • A three (3) to thirty-six (36) month court-ordered DUI alcohol education program (aka DUI school).13

The exception is if you are convicted of DUI causing injury (in a non-commercial or commercial vehicle). This offense is a California wobbler, which means that it may be charged as a misdemeanor orfelony.14

Charged as a felony, DUI causing injury can carry a lengthy state prison sentence.15

2.2. Will my commercial license be suspended for a DUI under VC 15300?

A school bus driver with a DUI will have his/her commercial license suspended for at least a year.

California DUI penalty law treats commercial license holders differently from other DUI defendants when it comes to driver's license suspensions.

First-time DUI offenders who do not hold commercial driver's licenses will have their licenses suspended for six (6) months. But in most cases this suspension is converted to a restricted license that allows them to drive to and from their jobs and DUI school.16

In contrast, for a first-time DUI conviction (whether under VC 23152(d) or under another law), the consequences include a suspension of your commercial license for one (1) year under Vehicle Code 15300 VC. This will be the case regardless of whether your DUI occurred while you were driving a commercial vehicle or not. AND there is no equivalent of a restricted license for commercial driver's licenses.17

Not only that—but if you are convicted of DUI a second or subsequent time, you will lose your commercial driver's license for life.18

According to Lancaster DUI defense attorney John Murray19:

“California DUI law allows for a restricted license for most DUI offenders because lawmakers recognize that the loss of a person's livelihood is too severe a punishment for a simple DUI. Defendants who don't drive commercial vehicles for a living are permitted to drive to the extent necessary to keep their jobs after a DUI. But if you hold a commercial license, and that license is suspended after a DUI, you are effectively being punished by having your ability to work taken away for a year. This is an incredibly harsh—and unfair—system.”

3. How Can I Fight Commercial License DUI Charges in California?

While there are no California DUI defenses that are specific to commercial drivers and VC 23152(d), a skilled criminal and DUI defense attorney should be familiar with the general DUI defenses that are most likely to help a commercial license holder fight DUI charges and keep his/her license.

DUI chemical breath test results are not always accurate.

The most common effective DUI defenses for commercial drivers include:

The results of your DUI chemical test were not accurate

Chemical blood or breath test results may seem like ironclad evidence. But in fact there are a variety of reasons why these results might not be reliable in your commercial driver DUI case. These include:

  • The DUI chemical testing instrument might not have been properly calibrated;
  • The defendant may suffer from GERD, acid reflux or heartburn—all of which can produce false high BAC levels; and
  • The driver may have had a rising blood alcohol level at the time of the DUI blood or breath test—which means that his/her BAC may actually have been lower when s/he was driving.

Police did not use proper procedures when they stopped or arrested you

Even if a commercial driver was DUI (under Vehicle Code 23152(d) VC or any other law), if the police didn't follow proper protocol, the charges against him/her may ultimately have to be dismissed.

Maybe the officers didn't adhere to the mandatory police procedures set forth in Title 17.

Or maybe the police interrogated the driver after placing him/her under arrest but failed to read Miranda rights. In that case, the driver's incriminating statements would have to be excluded from evidence.

Finally, if the police stopped, detained or arrested the driver for commercial license DUI without probable cause, the charges will likely be reduced or dismissed.

The bottom line is that innocent commercial drivers are wrongly accused of DUI all the time. There are almost always defenses that can help these defendants beat the charges.

Call us for help…


For questions about DUI laws and commercial driver's license holders, including Vehicle Code 23152(d) VC and Vehicle Code 15300 VC, or to discuss your case confidentially with one of our California criminal defense attorneys, do not hesitate to contact us at Shouse Law Group.

We have local criminal law offices in and around Los Angeles, San Diego, Orange County, Riverside, San Bernardino, Ventura, San Jose, Oakland, the San Francisco Bay area, and several nearby cities.

For more information on Nevada “commercial license drivers” DUI laws, please see our page on Nevada “commercial license drivers” DUI laws.

Additional Resources:

California DMV, Suspended License in California

Legal References:

  1. Vehicle Code 23152 VC.
  2. Same.
  3. Vehicle Code 15300 VC.
  4. Same.
  5. Vehicle Code 13352.4 VC – Restricted driver's licenses [doesn't apply to DUI with a commercial license]. 
  6. Judicial Council of California Criminal Jury Instructions (“CALCRIM”) 2110 – Driving Under the Influence.
  7. Vehicle Code 23152 VC – Driving under influence [including commercial driver DUI]; blood alcohol percentage; presumptions, endnote 1 above.
  8. Vehicle Code 23153 VC.
  9. Vehicle Code 15210 VC.
  10. Vehicle Code 23152 VC.
  11. Vehicle Code 15278 VC – Vehicles for which endorsement required [commercial driver's license required].

    See also California DMV, Who Needs a Commercial Driver's License?

  12. Vehicle Code 15210 VC – Definitions applicable to chapter [definition of commercial vehicle for purposes of DUI laws]. 
  13. These are examples of the penalties and sentence conditions for California Vehicle Code 23152, including VC 23152(d). They are a summary of the punishments imposed for first through third DUI offenses (for either commercial or non-commercial drivers) set forth in Vehicle Code 23538, 23540 and 23546 VC.
  14. See Vehicle Code 23554 to 23568 VC.
  15. Same.
  16. Vehicle Code 13352.4 VC – Restricted driver's licenses [doesn't apply to DUI with a commercial license], endnote 5 above.

    Vehicle Code 13352 VC – Conviction for driving under the influence or engaging in speed contests or exhibitions of speed; terms of suspension or revocation of license [non-commercial license]; eligibility for restricted license; reinstatement conditions. 

  17. Vehicle Code 15300 VC – First time violations [for commercial license holders convicted of DUI]; hazardous material violations, endnote 3 above.
  18. Vehicle Code 15302 VC – More than one violation [loss of commercial driving privileges after more than one DUI].
  19. Lancaster DUI defense attorney John Murray is a leading expert in California DUI defense, including finer distinctions like the differing penalties for commercial and non-commercial license holders. He has extensive experience both in the court systems of Los Angeles County and Ventura County and in California DMV hearings.


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