DUI checkpoints — also called sobriety checkpoints — are a regular occurrence on the roads of Southern Maryland, particularly on holiday weekends, during summer months, and around major events. While these checkpoints are generally legal in Maryland, you still have important constitutional rights during a checkpoint stop. Knowing what officers can and cannot require of you can help you protect yourself if you encounter a checkpoint in Charles County, Calvert County, St. Mary’s County, or Prince George’s County. At SoMD Criminal Defense, we defend clients who have been charged with DUI and DWI after checkpoint stops.
Are DUI Checkpoints Legal in Maryland?
Yes. The U.S. Supreme Court held in Michigan Department of State Police v. Sitz (1990) that sobriety checkpoints are constitutional, finding that the government’s interest in preventing drunk driving outweighs the minimal intrusion on individual drivers. Maryland has embraced this ruling, and law enforcement agencies throughout Southern Maryland regularly conduct DUI checkpoints. However, the legality of a checkpoint depends on whether it was conducted in compliance with specific legal requirements designed to prevent arbitrary or discriminatory enforcement.
For a checkpoint to be legally valid, it must be authorized by supervisory law enforcement personnel — not decided by officers in the field. There must be a systematic method for stopping vehicles, such as stopping every vehicle or every third vehicle, to prevent officers from using discretion to target specific drivers. The checkpoint must be clearly marked with signs, lights, and visible law enforcement presence so that approaching drivers are aware that a checkpoint is ahead. Officers must use a standardized process and cannot extend the duration of the stop beyond what is reasonably necessary to achieve the checkpoint’s purpose.
Your Rights at a DUI Checkpoint
Even though DUI checkpoints are legal, you retain important constitutional rights during the encounter. Understanding these rights can protect you from self-incrimination and unlawful searches.
You must stop when directed to do so at a checkpoint. Failing to stop or attempting to evade a checkpoint can result in additional charges, and officers may pursue you if you attempt to avoid the checkpoint. However, making a legal turn before reaching the checkpoint is generally permissible and cannot, by itself, serve as the basis for a traffic stop.
You are required to provide your driver’s license, registration, and proof of insurance when requested. Maryland law requires drivers to carry and produce these documents upon request by law enforcement. Failing to provide these documents can result in citations and may give officers additional reasons to extend the stop.
You do not have to answer questions about where you have been, whether you have been drinking, or how much you have consumed. The Fifth Amendment protects you from self-incrimination, and you can politely decline to answer these questions. Simply say something like, “I respectfully decline to answer that question” or “I would prefer not to discuss my evening.” You should be polite and calm, but you do not need to provide information that could be used against you.
You generally do not have to perform field sobriety tests. Standardized field sobriety tests — such as the walk-and-turn, one-leg stand, and horizontal gaze nystagmus test — are voluntary in Maryland. Officers may ask you to perform these tests, but you can decline. Keep in mind that declining may lead the officer to form opinions about your sobriety based on other observations, and in some situations may lead to arrest based on the officer’s other observations of impairment.
Breathalyzer Tests and Implied Consent
Maryland’s implied consent law creates important obligations regarding chemical testing. Under Transportation Article § 16-205.1, by driving on Maryland roads, you have impliedly consented to submit to a breath test if an officer has reasonable grounds to believe you are impaired. However, the implied consent law applies to the formal breath test administered at the police station, not to preliminary breath tests (PBTs) administered roadside.
Preliminary breath tests administered at the checkpoint are generally voluntary, and you can refuse them. However, refusing the formal breath test at the station after arrest triggers administrative penalties including a 270-day license suspension for a first refusal — which is actually longer than the 180-day suspension for a failed test. This does not mean you should always submit to testing, but the decision should be made with awareness of the consequences.
When Can Officers Search Your Vehicle at a Checkpoint?
A DUI checkpoint does not give officers blanket authority to search your vehicle. Officers can only search your car if they have probable cause to believe it contains evidence of a crime, you give consent to a search, they see contraband or evidence in plain view, or they have arrested you and are conducting a search incident to arrest. If an officer asks to search your vehicle at a checkpoint, you have the right to refuse. Your refusal cannot be used as probable cause for a search. If an officer conducts a search over your objection, your defense attorney can challenge the legality of the search and seek suppression of any evidence found.
Common Checkpoint Mistakes That Help Your Defense
In our experience defending DUI cases originating from checkpoints in Charles County, Calvert County, and St. Mary’s County, law enforcement officers sometimes make errors during checkpoint operations that can be used to challenge the charges. Common issues include failure to follow the checkpoint’s predetermined vehicle-stopping plan, inadequate signage or lighting making the checkpoint difficult to identify, extending the duration of stops without reasonable suspicion, improper administration of field sobriety tests, failure to document the checkpoint authorization properly, and officers using personal discretion rather than the systematic plan to select which vehicles to stop. If any of these issues exist in your case, the evidence obtained at the checkpoint may be subject to suppression.
Where DUI Checkpoints Are Common in Southern Maryland
DUI checkpoints in Maryland are most common on weekends, holidays, and during enforcement campaigns such as “Drive Sober or Get Pulled Over.” In Southern Maryland, roadblocks are frequently set up in:
- Prince George’s County – high-traffic areas like Route 4, Route 5, and the Beltway
- Charles County – along Route 301 near Waldorf, La Plata, and White Plains
- Calvert County – especially near Prince Frederick and Chesapeake Beach
- St. Mary’s County – in areas like Lexington Park, California, and Leonardtown
Police often target locations with higher rates of DUI arrests or prior accident data, and checkpoints may be coordinated between multiple county agencies.
What to Do at a DUI Checkpoint
If you are stopped at a checkpoint, stay calm and remember these steps:
- Provide your license, registration, and proof of insurance when asked.
- You are not required to answer questions about where you have been or whether you have been drinking. Politely state that you would like to speak with your attorney before answering.
- Be respectful and cooperative in demeanor, even while declining to answer incriminating questions.
- Do not consent to a vehicle search; officers need probable cause to search without your consent.
Contact a Southern Maryland DUI Defense Attorney
If you have been charged with DUI or DWI after a checkpoint stop in Maryland, do not assume the charges will stick. Checkpoint procedures must meet strict constitutional requirements, and violations of your rights can lead to dismissal of the charges. At SoMD Criminal Defense, Jeremy Widder and Kathryn Batey bring years of experience to every DUI case and know how to challenge checkpoint stops effectively.
Call (301) 818-0389 or contact us online for a free consultation. We serve clients in Waldorf, La Plata, Prince Frederick, Leonardtown, Upper Marlboro, and throughout Southern Maryland. This article provides general information about DUI checkpoint rights in Maryland and should not be relied upon as legal advice for your specific situation.
Frequently Asked Questions
Can I turn around to avoid a DUI checkpoint?
Making a legal turn before reaching a checkpoint is generally permissible and cannot, by itself, justify a traffic stop. However, if you make an illegal U-turn, violate a traffic law, or drive erratically while attempting to avoid the checkpoint, officers may have grounds to stop you for the traffic violation. The legality of the stop depends on whether the officer observed an independent traffic violation.
Do I have to roll down my window all the way at a checkpoint?
Maryland law does not require you to roll your window down completely. You need to roll it down enough to communicate with the officer and pass documents back and forth. Some drivers choose to roll the window down only partway, which is their right. However, this may prolong the encounter or draw additional attention from officers.
Can I be arrested at a checkpoint even if I pass the breath test?
Yes. An officer can arrest you for DUI based on other evidence of impairment even if your breath test result is below 0.08. Maryland law allows DUI charges based on impairment from alcohol, drugs, or a combination of both. Observable signs of impairment such as slurred speech, bloodshot eyes, impaired coordination, and the smell of alcohol or marijuana can support an arrest independent of breath test results.
