DUI Checkpoints: Are They Legal, and What Happens at One?
The federal rule, why some states do not use them, and what to expect if you drive through one.
Quick Answer
The U.S. Supreme Court held in 1990 that properly run sobriety checkpoints do not violate the Fourth Amendment. States are free to be stricter, though, and some do not allow or do not use them. Checkpoints must follow neutral, pre-set rules, and the Court has said checkpoints aimed at general crime control are not allowed.
Educational information, not legal advice. This is a general national overview. DUI and DWI laws are set by each state and change often, so details differ where you are. Use the state guides linked below and speak with a licensed attorney in the state where you were stopped or charged.
What a sobriety checkpoint is
A sobriety checkpoint, also called a DUI checkpoint or roadblock, is a location where police stop vehicles in a set pattern, for example every car or every third car, to look for signs of impaired driving. Officers briefly talk to the driver. If they see signs such as the smell of alcohol, slurred speech, or bloodshot eyes, they can direct the driver to a separate area for further investigation, which may include field sobriety tests.
NHTSA's Countermeasures That Work guide lists publicized sobriety checkpoints as one of the enforcement strategies states use to deter impaired driving, and notes that most, but not all, states permit them.
Sources: NHTSA: Publicized sobriety checkpoints (Countermeasures That Work) · NHTSA: Drunk driving
The federal rule
In Michigan Department of State Police v. Sitz (1990), the Supreme Court held that a highway sobriety checkpoint program is a seizure, but a reasonable one: the state's interest in preventing drunk driving outweighed the brief intrusion on drivers. The Court upheld the checkpoint even though officers had no individual suspicion about any driver.
In City of Indianapolis v. Edmond (2000), the Court struck down a checkpoint whose primary purpose was detecting ordinary drug crime. The Court said its decision did nothing to change the status of the sobriety checkpoints approved in Sitz, and distinguished them because their purpose was highway safety, not general crime control.
Sources: Michigan Dept. of State Police v. Sitz (U.S. Supreme Court, 1990) · City of Indianapolis v. Edmond (U.S. Supreme Court, 2000)
Why the answer still depends on your state
The Sitz decision decides only the federal Fourth Amendment question. A state can prohibit checkpoints, or set tighter rules, under its own constitution or statutes. Some states do not conduct sobriety checkpoints at all, and others set requirements on advance publicity, supervision, locations, and how vehicles are selected.
Where laws vary: whether checkpoints are used in your state, and the rules they must follow, are set by state law and court decisions. Check your state's guide and a current source before relying on a general summary.
Sources: Michigan Dept. of State Police v. Sitz (U.S. Supreme Court, 1990) · NHTSA: Publicized sobriety checkpoints (Countermeasures That Work)
What to expect if you drive through one
- You will usually be directed by signs, cones, and marked patrol vehicles. Slow down and follow the officers' directions.
- Have your license, registration, and proof of insurance ready, as you would at any traffic stop.
- The first contact is typically brief. An officer may ask a short question and look for signs of impairment.
- If the officer suspects impairment, you may be asked to pull aside for further screening. Field sobriety tests and chemical tests are separate decisions, each governed by state law; see the guide on field sobriety tests.
- Turning around before the checkpoint is often lawful if you do it legally and safely, but doing so illegally, or showing other signs of impairment, can give officers a reason to stop you. State law controls here.
General guidance, not drawn from a single source. Check your state guide for the law that applies to you.
If you are arrested at a checkpoint
An arrest at a checkpoint follows the same path as any other DUI arrest: a possible chemical test, an administrative license action with a short deadline to request a hearing, and a criminal case. Your attorney can review whether the checkpoint met the requirements of your state's law and the Constitution. See the guide on what happens after a DUI arrest and your state guide for the deadline that applies.
Sources: Michigan Dept. of State Police v. Sitz (U.S. Supreme Court, 1990) · City of Indianapolis v. Edmond (U.S. Supreme Court, 2000)