Thirty years ago, the U.S. Supreme Court determined that a suspicionless investigatory intrusion on a motorist was justified based on the public’s interest in reducing driving under the influence (DUI). The high court was considering the constitutionality of sobriety check points when it decided Michigan Department of State Police v. Sitz, 496 U.S. 444 (1990).

In a 6-3 decision, the court held that sobriety check points did not violate the Fourth Amendment. The court noted that “no one can seriously dispute the magnitude of the drunken driving problem or the states’ interest in eradicating it.” The court then found that “the measure of the intrusion on motorists stopped briefly at sobriety checkpoints—is slight.”