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The Constitutionality of Roadblocks to Catch Drunk Drivers

Jonathan S. Willett Jan. 20, 2018

The Fourth Amendment generally protects the right of people to be free from “unreasonable searches and seizures.” In order for a search or seizure to be reasonable under the Fourth Amendment, it must usually be based on individualized suspicion of wrongdoing. In 1979, the U.S. Supreme Court held in Delaware v. Prouse that randomly stopping an automobile to apprehend unlicensed drivers and unsafe vehicles constitutes an unreasonable seizure under the Fourth Amendment, where the officer does not have reasonable suspicion that a motorist has violated the law. The Court reasoned that the State’s interest in ensuring roadway safety does not justify discretionary spot checks that intrude on the privacy of motorists.

However, the Court has since made a limited exception for DUI sobriety checkpoints, holding that officers may perform random spot checks to catch drunk drivers with no requirement of individualized suspicion.

Suspicionless Seizures at Highway Sobriety Checkpoints

While some states have ruled that DUI checkpoints are illegal under their state constitutions, the majority of states and the U.S. Supreme Court have ruled that brief seizures at DUI sobriety checkpoints are legal when conducted in a particular manner. In 1990, the Court upheld a state’s use of highway sobriety checkpoints as consistent with the Fourth Amendment in Michigan Department of State Police v. Sitz, where:

  • The checkpoints are selected pursuant to guidelines; and

  • Uniformed officers briefly stop every vehicle.

Analogizing highway sobriety checkpoint programs to the checkpoints used at fixed borders to intercept illegal aliens (which have also been upheld as constitutional), the Court reasoned that the level of intrusion from sobriety spot checks is minimal when compared to the magnitude of the public interest in eradicating drunk driving.

Drug Interdiction Roadblocks

On the same reasoning, the Court subsequently ruled that a highway checkpoint program for the purpose of interdicting illegal narcotics violates the Fourth Amendment, where officers make stops without individualized suspicion. Specifically, the Court struck down the operation of drug checkpoints in City of Indianapolis v. Edmund, holding that the primary purpose of the Indianapolis checkpoint program was “ultimately indistinguishable from the general interest in crime control.”

While the intrusion from sobriety checkpoints is justified by the magnitude of the public interest in getting drunk drivers off the road, the intrusion from drug interdiction roadblocks cannot be so justified (because drug interdiction roadblocks serve only the general purpose of investigating crime). Accordingly, the balance of a motorist’s right to privacy against the general public interest in crime control does not tip in favor of the State when assessing the constitutionality of a checkpoint where the primary purpose is to interdict drugs.

Information-Seeking Stops

Emphasizing that the ruling in Edmund does govern the outcome of every case that involves suspicionless highway stops, the U.S. Supreme Court upheld the constitutionality of suspicionless information-seeking stops in the 2004 decision of Illinois v. Lidster. In that case, law enforcement officers set up a highway checkpoint to obtain information from motorists about a hit-and-run accident that had occurred about one week earlier in the same location, briefly asking the motorists whether they had seen anything and handing each driver a flyer describing the accident. In the course of the operation of this checkpoint, officers arrested Lidster for DUI.

The Court distinguished the information-seeking checkpoints in Lidster from the drug interdiction roadblocks in Edmund, reasoning that the primary purpose of the information-seeking stop was for help in providing information about a crime that was most likely committed by someone other than the vehicle occupant. In contrast, the primary purpose of the spot checks in Edmund was to determine whether a vehicle’s occupants were committing a crime. Accordingly, the intrusion on a motorist’s Fourth Amendment rights from the brief information-seeking stop in Lidster was minimal compared to “the gravity of the public concerns served by the seizure.”

DUI Sobriety Checkpoints Site Operations

In order to conduct DUI checkpoints within the limits of the Fourth Amendment, law enforcement officers should operate stops in a manner minimally intrusive on the rights of motorists. Some of the characteristics of a constitutionally permissible DUI sobriety checkpoint might include:

  • Checkpoint locations determined by commanders or first-line supervisors

  • Advance publicity of the checkpoint

  • Warning signs placed along the highway to notify motorists

  • Adequate lighting

  • Ample room to conduct the stop at a safe location

  • Officers in full uniform and readily identifiable