Are DUI checkpoints legal in California?

DUI checkpoints have mostly been upheld as legal in California. Nevertheless, if you are arrested at a DUI sobriety roadblock, you may be able to challenge your arrest on constitutional grounds.

While the police do not need probable cause to stop you at a checkpoint, the checkpoint itself must meet certain requirements under both the United States Constitution and the California Constitution.

The legal requirements for California DUI sobriety checkpoints are:

1. Supervising officers must make all operational decisions;
2. The criteria for stopping you must be neutral;
3. The checkpoint must be reasonably located;
4. Adequate safety precautions must be taken;
5. The checkpoint’s time and duration should reflect “good judgment”;
6. The checkpoint must exhibit sufficient indicia of its official nature;
7. You should be detained for a minimal amount of time; and
8. Roadblocks should be publicly advertised in advance.¹

If a roadblock does not meet these requirements, and if you are arrested, you may be able to defend against drunk driving charges.

Below, our California DUI defense attorneys answer the following frequently asked questions:

• 1. Are DUI checkpoints constitutional?
• 2. What can I expect?
• 3. What are the rules?
• 4. Can I turn around to avoid a DUI checkpoint?
• 5. Can I refuse to cooperate?
• 6. What if I am caught without a license?
• 7. Advanced Notice of Checkpoints
• Additional Resources

1. Are DUI checkpoints constitutional?

DUI sobriety roadblocks have been held valid under both the United States and California constitutions.²

The California Supreme Court has held that DUI checkpoints are “administrative inspections,” like airport screenings.³ As such, they are an exception to the Fourth Amendment rule that an officer must have probable cause or reasonable suspicion to initiate a drunk driving investigation.

2. What can I expect?

The law enforcement agency that is operating a California sobriety roadblock will section off a portion of the road. This will usually cause vehicles to merge into one or two lanes before coming to a stop.

The officer will ask you to roll down the window. Then the officer will ask to see your driver’s license and registration.

The officer will usually also engage you in a brief discussion. This dialogue helps the officer evaluate whether you may be driving under the influence.

Factors Leading to an Arrest

An officer at a California drunk driving checkpoint is looking to see whether you:

• Fumble when reaching for your license and registration,
• Smell of alcohol,
• Have trouble answering the officer’s questions,
• Have any alcoholic beverages, drugs or drug paraphernalia in the vehicle, or
• Have slurred speech, red, watery eyes, or any other signs of physical impairment.⁴

If signs of impairment are present, the officer may ask you to:

• Submit to a mouth swab test to determine if drugs are present in your system,
• Perform field sobriety tests (“FSTs”), and/or
• Take a Preliminary Alcohol Screening (“PAS”) breath test.

In some California counties, the police may also ask you to submit to a cheek swab to test for driving under the influence of marijuana or other drugs.

Potential Charges

Based on the results of these tests, the officer may have probable cause to believe that you are:

• Driving under the influence of alcohol–Vehicle Code 23152(a) VC,
• Driving with a BAC of .08 or greater–Vehicle Code 23152(b) VC,
• Driving under the influence of drugs (DUID)–Vehicle Code 23152(f) VC, or
• Guilty of underage DUI, commercial license DUI, or DUI by a taxi, limo or ride-sharing driver.

3. What are the rules?

Ingersoll v. Palmer is the landmark California Supreme Court case that sets forth eight “functional guidelines” to determine whether a DUI checkpoint is constitutional.⁵ There is no minimum number that is needed in order for a specific roadblocks to meet this test.

Rather, the court must balance:

1. The interest of the state in preventing drunk driving, against
2. The “subjective intrusion” on motorists–including the potential for generating fear and surprise.⁶

Remember that checkpoints are not in and of themselves unconstitutional.⁷ Failure of the police to follow strict procedures, however, may make a specific roadblock unconstitutional.⁸

Let’s take a brief look at these eight factors one by one.

1) Supervising Officers Must Make All Operational Decisions

Supervising officers (as opposed to field officers) must decide where, how, and when sobriety checkpoints will operate.⁹ This is to “reduce the potential for arbitrary and capricious enforcement.”¹⁰

2) The Criteria for Stopping Motorists Must Be Neutral

Supervising officers need to decide ahead of time which cars are to be stopped. Field officers may not make this decision.

The decision must be made using “neutral mathematical selection criteria.” Examples are stopping every third car, five consecutive cars out of every ten, etc.

Stopping only certain makes or model years of car, or stopping only drivers fitting a certain age or ethnic profile, is NOT acceptable.¹¹

3) The Sobriety Checkpoint Must Be Reasonably Located

The sobriety checkpoint must be set up in high DUI areas.¹²

4) Adequate Safety Precautions Must Be Taken

Supervising officers must consider safety when choosing where to set up a California DUI roadblock.¹³

Safety factors include:

• traffic patterns,
• street layout, and
• making the roadblock clearly visible to approaching drivers.¹⁴

5) The Checkpoint’s Time and Duration Should Reflect “Good Judgment”

Supervising officers are expected to use “good judgment” in setting the time of day and duration of a roadblock. Effectiveness must be weighed against the intrusiveness to drivers.¹⁵

6) The Checkpoint Must Clearly Show its Official Nature

You should be able to see clearly that you are approaching an official DUI stop. This helps minimize fear and surprise.¹⁶

A sobriety roadblock can be indicated by:

• warning signs,
• flashing lights,
• marked police cars, and
• the presence of uniformed police officers.¹⁷

7) Drivers Should Be Detained a Minimal Amount of Time

You should be detained at a California DUI checkpoint only long enough for the officer to question you briefly and to look for signs of intoxication such as:

• alcohol on your breath,
• slurred speech, and
• glassy or bloodshot eyes.¹⁸

If you show no signs of impairment, you should be permitted to drive on without further delay.¹⁹ Any further investigation must be based on probable cause or reasonable suspicion.²⁰

8) DUI Roadblocks Should Be Publicly Advertised in Advance

Ideally, DUI checkpoints should be advertised in advance. However, lack of advance publicity does not, by itself, make them unconstitutional.²¹

Law enforcement agencies generally try to publicize sobriety roadblocks about a week in advance. Notice can often be found in or on:

• advertising,
• law enforcement websites,
• local newspapers, and
• local news stations.

4. Can I turn around to avoid a DUI checkpoint?

There is no law preventing you from intentionally avoiding a DUI roadblock. You may turn around or take another route–as long as it is safe to do so.

Police typically give you enough warning to allow you to safely avoid the checkpoint.²² In addition, departmental rules often prohibit officers from stopping you solely because you intentionally avoided the stop.

Still, normal traffic rules still apply. Police officers may pull you over if, while avoiding a checkpoint, you:

• commit a traffic violation,
• have a defect, such as a broken tail light, on the vehicle, or
• display signs of obvious intoxication.²³

5. Can I refuse to cooperate?

Vehicle Code 2814.2(a) VC requires you to stop and submit to California sobriety checkpoints.²⁴

So once you are stopped, you may not refuse to comply with the officer’s instructions. If you do, you will likely be charged with an infraction.

However, this does not mean that you have to submit to field sobriety tests or pre-arrest breath tests or cheek swabs. These tests are optional, and you may refuse them without penalty (though doing so may result in you being arrested for drunk driving anyway).

If, however, you are lawfully arrested, refusing a post-arrest breath test or blood test is considered a chemical test refusal. Refusing a post-arrest test has consequences, including an automatic one-year suspension of your driver’s license.

6. What if I am caught without a license?

What happens if you are caught without a license at a California DUI roadblock depends on whether:

1. You have a valid driver’s license but just do not have it with you, or
2. You do not have a valid driver’s license at all.

You Left Your License at Home

If you are not carrying your license while driving, you can be charged with Vehicle Code 12951 – failure to display a driver’s license. This will likely be charged as an infraction, which carries a fine.

If you can later prove that you did have a valid license at the time of the stop, there is a good chance that the charge will be dismissed.

You Have No License

It is more serious if you do not have a license at all or if your license has been suspended or revoked. In this case, you can be charged with:

• Vehicle Code 12500 – driving without a valid license, or
• Vehicle Code 14601 – driving on a suspended license.

However, your vehicle will not be impounded as long as:

1. This is the only charge against you (that is, you are not also arrested for drunk driving or an outstanding warrant),²⁵ and
2. You (or the registered owner of the vehicle if it is someone else) authorize the release of the vehicle to a licensed driver.²⁶

California law prohibits the immediate impoundment of a vehicle at a sobriety checkpoint if your only offense is driving without a valid license.²⁷

7. Advanced Notice of Checkpoints

Law enforcement’s official releases are the best way to find out about DUI checkpoints in advance. Other sources of advance information about when and where sobriety roadblocks will be held include:

• police department websites,
• local newspapers and news websites, and
• local TV news.

That said, as discussed above, advance public notice of upcoming checkpoints is not required. So not all of them will be publicized.

Smartphone Apps

There are many apps on the market that purport to warn drivers of upcoming sobriety roadblocks. In addition, the traffic data app Waze reports the location of police, including at sobriety roadblocks. (Remember that Waze’s data is user-generated and may not be accurate or comprehensive.)

Note that apps come and go depending on the current state of the law and whether the publisher has updated them along with the platform’s operating system updates.

For instance, in June 2011, Apple (the maker of iPhones) and Research in Motion (the maker of Blackberries) banned the sale of apps that:

• identify DUI checkpoints not published by law enforcement agencies, or
• encourage and enable drunk driving.²⁸

This came after four United States senators expressed concerns that such apps were “giving drunk drivers a free tool to evade roadblocks.”²⁹

However, a recent Google search revealed that such apps are still available for IOS (for iPhones) as well as for phones that run Google’s Android OS.

Additional Resources

For more information, refer to the following:

1. Alcoholics Anonymous – 12-step program for overcoming alcoholism.
2. Drunk Driving Overview – NHTSA page on drunk driving statistics and prevention.
3. Impaired Driving: Get the Facts – CDC fact sheet on impaired driving.
4. Driving Under the Influence (DUI) – California DMV page on driver license suspension for DUIs.
5. MADD – Non-profit organization devoted to stopping drunk driving.

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