DUI Checkpoints

When police pull motorists over, they must have probable cause. DUI checkpoints, however, work a little differently. Typically, the police set up roadblocks near highways or busy intersections and stop drivers to look for signs of impairment. DUI roadblocks are most likely to be set up when there is higher potential for drunk driving, like around holidays or big events. This practice is allowed in many states in order to combat drunk driving and it is believed to prevent numerous injuries and fatalities every year.

The Rules of Sobriety Checkpoints

Sobriety checkpoints have naturally been the subject of controversy as the authorities are allowed to stop drivers and speak with them without having probable cause. There are rules governing these checkpoints and the police do not have free rein to stop every driver for no reason. These "random" checks are only partly left to chance. The police must establish a pattern for stopping drivers, like stopping every fourth or fifth car. Police cannot opt to stop vehicles with a certain make or model or stop only those of a certain gender or race.

Probable Cause Still Applies After a Stop

Checkpoints are not meant to take up much of a sober driver's time and should generally last the same amount of time as a red light. Reasonable suspicion is needed for anything more than briefly stopping and questioning a driver. An officer can only ask a driver to undergo sobriety testing if there is evidence that would cause a reasonable officer to suspect intoxication. Examples of evidence may include the smell of alcohol on a motorist, slurred speech or an open alcohol container in the vehicle. To arrest or further detain a driver after testing, there must be more evidence that indicates impairment, like the results of a breath test or field sobriety testing.

Suipreme Court Justification for Checkpoints

After sobriety checkpoints were introduced, critics believed that these stops were a violation of the Fourth Amendment, which protects people against unlawful search and seizures. The legitimacy of checkpoints was upheld in 1990 in the U.S. Supreme Court decision Michigan Department of State Police v. Sitz. The court found that checkpoints do not violate the Fourth Amendment because the stops are only minimally invasive to drivers but are important to the state's "grave and legitimate" interest in reducing drunk driving.

Checkpoints and State Laws

DUI checkpoints are federally sanctioned, but states are not required to set up any roadblocks. There are 12 states that do not conduct checks:

  • Alaska
  • Idaho
  • Iowa
  • Michigan
  • Minnesota
  • Montana
  • Oregon
  • Rhode Island
  • Texas
  • Washington
  • Wisconsin
  • Wyoming

Indeed, checkpoints are illegal entirely according to the state constitutions of Minnesota, Oregon and Michigan. Texas’ interpretation of the SCOTUS decision makes random DWI stops illegal, while state court decisions prohibit them in Washington and Rhode Island.


Sobriety checkpoints have been found to reduce alcohol-related accidents and fatalities by 18 to 24 percent, according to the Centers for Disease Control and Prevention. Alcohol-related crashes cost America more than $132 billion every year, and it is estimated that communities save up to $23 for each dollar that funds checkpoints. Federal grants are sometimes used, which helps keep costs low.

The police are not required to announce when or where checkpoints will be conducted, but the public is frequently informed anyway. The act of announcing checkpoints act as a deterrent as people may be less willing to drink and drive, knowing the police are on the roadways looking for impaired drivers.

Get Legal Help

If you are arrested as the result of a DUI checkpoint, a DUI lawyer could help you learn what steps to take next. In some cases, checkpoints are found to be run incorrectly, which could invalidate evidence of a DUI. Additionally, if an officer did not have reasonable suspicion to test you further, evidence against you may be barred from being used in court.

The information on this page is meant to provide a general overview of the law. The laws in your state and/or city may deviate significantly from those described here. If you have specific questions related to your situation you should speak with a local attorney.

Additional Drunk Driving Articles

Search LawInfo's Drunk Driving Resources