California DUI Sobriety Checkpoints: Frequently Asked Questions

Busted at a DUI checkpoint? Advice from a former D.A.

More info at Arrested for DUI at a sobriety checkpoint or police roadlblock? Can you fight the case? Are DUI checkpoints legal or do they violate your rights? What procedures must police follow at checkpoints in order to have probable cause to make you exit your vehicle? In this video, a former DUI prosecutor—now criminal defense lawyer—answers all of these questions. Under California law, police must follow strict procedures in setting up and administering a DUI sobriety checkpoint. When they fail to adhere to these procedures, a good DUI defense attorney can challenge the arrest and often get the charges reduced or dismissed.

Drivers arrested at a DUI sobriety checkpoint may be able to challenge their arrest on constitutional grounds. While the police do NOT need "probable cause" to stop drivers 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 motorists 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. Drivers should be detained for a minimal amount of time; and
  8. Roadblocks should be publicly advertised in advance.1

If a checkpoint does not meet these requirements, a driver arrested at such an inspection may be able to defend against DUI charges

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

1. Are California DUI checkpoints constitutional?

DUI sobriety checkpoints 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 DUI investigation.

2. What can a driver expect when stopped?

The law enforcement agency that is operating a California sobriety checkpoint 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 the driver to roll down the window. Then the officer will ask to see the driver's license and registration.

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

Factors that may lead to a DUI arrest at a California sobriety checkpoint

Specifically, an officer at a California DUI checkpoint is looking to see whether the driver:

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

If signs of impairment are present, the officer may commence a drunk driving investigation. During the investigation, the officer may ask the driver to:

In some California counties, the police may also ask the driver to submit to a cheek swab to test for DUI of marijuana or other drugs.

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

3. What are the rules and regulations for DUI sobriety checkpoints in California?

Courts in California will look at eight different factors to determine whether a checkpoint was legal. There is no minimum number that is needed in order for a specific checkpoint 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.5

As San Bernardino DUI defense lawyer Michael Scafiddi6 explains:

"When I have a client who is arrested at a California DUI checkpoint, I critically examine the sobriety checkpoint itself. If any of the legal requirements that relate to these DUI traps are not satisfied, I may be able to get my client's DUI case dismissed."

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

Courts have held that DUI sobriety checkpoints are constitutional as long as they abide by certain legal requirements.

The California Supreme Court case of Ingersoll v. Palmer

Ingersoll v. Palmer is the landmark case relating to California DUI checkpoints. In it, the California Supreme Court set forth eight “functional guidelines” to determine whether a DUI checkpoint is constitutional.8

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

1. Supervising officers must make all operational decisions

Supervising officers (as opposed to field officers) must determine where, how, and when California 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 determine ahead of time which cars are to be stopped. Field officers may not make this determination.

The determination 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 in a location where there is a high incidence of DUI-related accidents or arrests.12

4. Adequate safety precautions must be taken

Supervising officers must consider safety when choosing where to set up a California DUI checkpoint.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 their “good judgment” in setting the time of day and duration of a checkpoint. Effectiveness must be weighed against the intrusiveness to drivers.15

6. The checkpoint must clearly show its official nature

Motorists should be able to see clearly that they are approaching an official DUI stop. This helps minimize fear and surprise on the part of law-abiding drivers.16

The official nature of 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

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

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

A driver who shows no signs of impairment 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 a sobriety checkpoint unconstitutional.21

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

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

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

There is no law preventing someone from intentionally avoiding a DUI checkpoint. A driver may turn around or take another route--as long as it is safe to do so.

As a practical matter, law enforcement agencies typically give drivers sufficient warning to allow them to safely avoid the checkpoint.22 In addition, departmental rules often prohibit officers from stopping motorists solely because they intentionally avoided the stop.

But normal traffic rules still apply. Police officers may pull someone over if, while avoiding a DUI checkpoint, he or she:

  • commits a traffic violation,
  • has a defect, such as a broken tail light, on the vehicle, or
  • displays signs of obvious intoxication.23

5. Can a driver refuse to cooperate?

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

So once someone is at a checkpoint, he/she may not refuse to comply with the officer's instructions. A driver who does so will likely be charged with a California infraction.

But this does not mean that a driver has to submit to field sobriety tests or pre-arrest breath tests or cheek swabs. These tests are optional and a driver may refuse them without penalty (though doing so may result in the driver being arrested for DUI anyway).

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

6. What if someone is caught driving without a license?

What happens to someone caught without a license at a California DUI roadblock depends on whether:

  1. The person has a valid driver's license but just doesn't have it with him or her, or
  2. The person does not have a valid driver's license at all.

License not on driver's person or in vehicle

A driver who is not carrying his or her license can be charged with Vehicle Code 12951, failure to display a driver's license. This will likely be charged as a California infraction and lead to payment of a fine.

And if the driver can later prove that he/she did have a valid license at the time of the stop, there is a good chance that the charge will be dismissed.

The driver does not have a valid license

It is more serious if the driver does not have a license at all or if his/her license has been suspended or revoked. In this case, he or she can be charged with:

But the driver's vehicle will not be impounded at the DUI checkpoint as long as:

  1. This is the only charge against the driver (that is, he/she is not also arrested for DUI or an outstanding warrant), and
  2. The driver (or the registered owner of the vehicle if it is someone else) authorizes the release of the vehicle to a licensed driver by the end of the checkpoint.25

The police can no longer automatically impound vehicles of unlicensed drivers

Before 2012, California law allowed officers to impound the vehicles of unlicensed drivers at California DUI checkpoints. Opponents of this practice argued that such vehicle seizures:

  • unfairly targeted undocumented immigrants who at the time were not permitted to obtain driver's licenses, but who needed cars for work,
  • constituted an unreasonable seizure in violation of the Fourth Amendment and
  • were motivated by financial incentives.26

In response to such criticisms, the California Legislature enacted Assembly Bill 353, now codified as California Vehicle Code 2814.2. That section prohibits the immediate impoundment of a vehicle at a sobriety checkpoint if the driver's only offense is driving without a valid license.27

7. How can people find out about DUI checkpoints in advance?

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 checkpoints will be publicized through those channels.

Are there smartphone apps that advise drivers of upcoming DUI checkpoints?

There are numerous 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 checkpoints. (But remember that Waze's data is user-generated and so 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 checkpoints.”29

But 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.

8. Examples of recent California sobriety roadblocks

In July 2018, the Oxnard police stopped almost 1,000 drivers and arrested three at a sobriety roadblock. The location was chosen because it was the site of recent arrests stemming from alcohol-related accidents.30

In June 2018, a sobriety checkpoint in Santa Maria, California resulted in nine arrests based on just 481 screen vehicles.31 One of these was for DUI. The other eight were for driver's license violations.

But not all sobriety checkpoints result in arrests. On a recent Friday night in June 2018, an 8-hour roadblock set up by the California Highway Patrol in Santa Clarita stopped 467 vehicles but resulted in no arrests. Only 11 drivers were even given field sobriety tests.32 However, the checkpoint was left up for the remainder of the weekend, during which the CHP made five arrests.

Arrested at a DUI checkpoint? Call us for help…

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If you or a loved one was arrested at a California DUI sobriety checkpoint, we invite you to contact us for a free consultation.

Call us at 855-LAWFIRM to set up a free consultation with an experienced California DUI lawyer in office or by phone.

We have local offices in Los Angeles, the San Fernando Valley, Pasadena, Long Beach, Orange County, Ventura, San Bernardino, Rancho Cucamonga, Riverside, San Diego, Sacramento, Oakland, San Francisco, San Jose and throughout California.

For information about Colorado DUI sobriety checkpoints, please see our article on Colorado DUI sobriety checkpoints.

For information about Nevada DUI sobriety checkpoints, please see our article on Nevada DUI sobriety checkpoints.

Legal References:

  1. Ingersoll v. Palmer (1987) 43 Cal.3d 1321.
  2. Michigan Dept. of State Police v. Sitz (1990) 496 U.S. 444, 110 S.Ct. 2481 (holding that DUI sobriety checkpoints do not violate the Fourth Amendment's prohibition against unreasonable searches); and, Ingersoll, endnote 1 (holding that DUI and driver's license checkpoints are not prohibited by the Unites States or California constitutions).
  3. Ingersoll, endnote 1, at 1331-2 (“The sobriety checkpoint presents a compelling parallel to the airport screening search. While the label "administrative search" is open to some criticism in application to either the airport search or the sobriety checkpoint stop, both, although they operate mechanically as a search or inspection for the violation of law, actually serve a primary and overriding regulatory purpose of promoting public safety. Their primary purpose is to prevent and deter conduct injurious to persons and property; they are not conventional criminal searches and seizures. The fact that sobriety checkpoint stops will lead to the detection of some individuals involved in criminal conduct does not alter the fundamental regulatory character of the screening procedure.")
  4. Ingersoll, endnote 1 above.
  5. Sitz, endnote 2 above, at 451.
  6. San Bernardino DUI defense lawyer Michael Scafiddi is a former DUI enforcement officer who now defends clients throughout the Inland Empire including Hemet, Palm Springs, Rancho Cucamonga, Riverside and San Bernardino.
  7. Ingersoll, endnote 1 (“It is illogical to suggest that an officer who has a reasonable suspicion an individual is driving under the influence of intoxicants and thus endangering the public may take corrective action, but that a law enforcement agency having knowledge that on any given night hundreds of drivers will be under the influence of intoxicants and thus endangering the public may not.”).
  8. Ingersoll, endnote 1 above (California DUI checkpoints are constitutional as long as they meet “functional guidelines for minimizing the intrusiveness of the sobriety checkpoint stop.”).
  9. See Ingersoll, endnote 1 above, at 1341. ("The decision to establish a sobriety checkpoint, the selection of the site and the procedures for the checkpoint operation should be made and established by supervisory law enforcement personnel, and not by an officer in the field. This requirement is important to reduce the potential for arbitrary and capricious enforcement.")
  10. Same at 1342.
  11. Same at 1342. ("A related concern is that motorists [at a California DUI checkpoint] should not be subject to the unbridled discretion of the officer in the field as to who is to be stopped. Instead, a neutral formula such as every driver or every third, fifth or tenth driver should be employed.")
  12. Same at 1343.
  13. Same at 1343. ("The location of [DUI] checkpoints should be determined by policy-making officials rather than by officers in the field. The sites chosen should be those which will be most effective in achieving the governmental interest; i.e., on roads having a high incidence of alcohol related accidents and/or arrests. Safety factors must also be considered in choosing an appropriate location.")
  14. Same at 1326 (“The location …was selected by taking into account frequency of drunk driving arrests and accidents, and safety factors such as traffic patterns and street layout…Warning signs [including a sign announcing a sobriety checkpoint] were posted. A cone taper diverted traffic to a single northbound lane. The signs and cone taper were set up according to Caltrans regulations for signing and lane closure.”)
  15. Same at 1345 (“N]o hard and fast rules as to timing or duration [of a DUI sobriety checkpoint] can be laid down, but law enforcement officials will be expected to exercise good judgment in setting times and durations, with an eye to effectiveness of the operation, and with the safety of motorists a coordinate consideration.”).
  16. Sitz, endnote 2 above, at 453.
  17. Ingersoll, endnote 1 above, at 1345 (“The [California DUI] roadblock should be established with high visibility, including warning signs, flashing lights, adequate lighting, police vehicles and the presence of uniformed officers. Not only are such factors important for safety reasons, advance warning will reassure motorists that the stop is duly authorized.”).
  18. Same at 1346. (“Minimizing the average time each motorist is detained [at a DUI sobriety roadblock] is critical both to reducing the intrusiveness of the stop on the individual driver and to maintaining safety by avoiding traffic tie-ups. As occurred in the Burlingame and CHP checkpoints, each motorist stopped should be detained only long enough for the officer to question the driver briefly and to look for signs of intoxication, such as alcohol on the breath, slurred speech, and glassy or bloodshot eyes.”)
  19. Same. (“If the driver does not display signs of impairment, he or she should be permitted to drive on without further delay [at the California sobriety checkpoint].”).
  20. Same. (“If the officer does observe symptoms of impairment, the driver may be directed to a separate area for a roadside sobriety test. At that point, further investigation would of course be based on probable cause, and general principles of detention and arrest would apply.”)
  21. People v. Banks (1993) 6 Cal.4th 926, 949. (“[T]he operation of a sobriety checkpoint conducted in the absence of advance publicity, but otherwise in conformance with the guidelines we established in [Ingersoll] does not result in an unreasonable seizure within the meaning of the Fourth Amendment to the United States Constitution.”)
  22. See, e.g., Ingersoll, endnote 1 above.
  23. Same at 1336, FN5.
  24. Vehicle Code 2814.2(a) VC -- DUI sobriety checkpoints. ("a) A driver of a motor vehicle shall stop and submit to a sobriety checkpoint inspection conducted by a law enforcement agency when signs and displays are posted requiring that stop.")
  25. Vehicle Code 2814.2(b)-(c) VC -- Unlicensed drivers stopped at DUI checkpoints. ("(b) Notwithstanding Section 14602.6 or 14607.6, a peace officer or any other authorized person shall not cause the impoundment of a vehicle at a sobriety checkpoint if the driver's only offense is a violation of Section 12500 [driving without a valid license]. (c) During the conduct of a sobriety checkpoint, if the law enforcement officer encounters a driver who is in violation of Section 12500, the law enforcement officer shall make a reasonable attempt to identify the registered owner of the vehicle. If the registered owner is present, or the officer is able to identify the registered owner and obtain the registered owner's authorization to release the motor vehicle to a licensed driver by the end of the checkpoint, the vehicle shall be released to either the registered owner of the vehicle if he or she is a licensed driver or to the licensed driver authorized by the registered owner of the vehicle.")
  26. Miranda v. City of Cornelius (2005) 429 F.3d 858. See also Ryan Gabrielson, Sobriety Checkpoints Catch Unlicensed DriversNew York Times, February 13, 2010.
  27. Vehicle Code 2814.2(b)-(c) VC -- Unlicensed drivers stopped at DUI checkpoints, endnote 25 above.
  28. See Dong Ngo, Apple bans DUI checkpoint apps on iOS devices,, June 8, 2011; Larry Copeland, BlackBerry backpedals on DUI checkpoint appsUSA Today, March 24, 2011.
  29. Catharine Smith, Senators Ask Apple To Ban DUI Checkpoint Alert AppsThe Huffington Post, March 23, 2011 (updated May 25, 2011).
  30. VC Star, "Police make 3 arrests at Oxnard DUI checkpoint," July 14, 2008.
  31. edhat Santa Barabara, "Santa Maria Police DUI Checkpoint Nets 9 Arrests," June 30, 2018.
  32. The Signal, "CHP sobriety checkpoint nets zero DUI arrests," June 18, 2018.

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