## Facts

- The Michigan Department of State Police created a sobriety checkpoint pilot program with written guidelines governing site selection, operations, and publicity.
- At designated checkpoints, officers stopped all vehicles and briefly observed drivers for signs of intoxication.
- Drivers showing possible intoxication were diverted for license and registration checks and, if warranted, further sobriety testing; others were promptly released.
- In a one-hour test operation conducted after midnight, 19 officers stopped about 126 vehicles; the average delay was about 25 seconds, and two drivers were arrested for driving under the influence.
- Licensed Michigan drivers sued for declaratory and injunctive relief to prevent implementation of the checkpoint program.

## Issues

1. Whether stopping motorists at fixed sobriety checkpoints without individualized suspicion is an unreasonable seizure under the Fourth and Fourteenth Amendments.
2. Whether, under the Brown v. Texas balancing test, the program’s asserted effectiveness and the intrusion on motorists justify the suspicionless stops.

## Decision

- The Supreme Court reversed the judgment enjoining the program, holding (6–3) that the checkpoint stops were reasonable under the Fourth Amendment.
- The Court treated a checkpoint stop as a “seizure,” but assessed reasonableness by balancing the state interest, the program’s ability to advance that interest, and the level of intrusion.
- The State’s interest in preventing drunk driving was substantial.
- The objective intrusion was minimal because most motorists experienced only brief questioning and observation and an average delay of about 25 seconds.
- The Court rejected the lower courts’ view that subjective intrusion (fear and surprise) was substantial, distinguishing fixed, guideline-based checkpoints from discretionary, random roving stops.
- The Court held the Constitution does not require the State to use the least intrusive or most empirically effective enforcement method; it was enough that the program could reasonably be said to advance the State’s interest.
- Justice Blackmun concurred in the judgment, emphasizing the strength of the governmental interest relative to the modest intrusion.
- Dissents argued that suspicionless stops are incompatible with Fourth Amendment protections and questioned the program’s effectiveness given the number of unimpaired motorists stopped.

## Legal Principles

- A vehicle stop at a fixed checkpoint is a Fourth Amendment seizure, but it can be reasonable without individualized suspicion.
- Reasonableness for checkpoint programs is assessed under a balancing test weighing: (1) the gravity of the public concern, (2) the degree to which the seizure advances that concern, and (3) the severity of interference with individual liberty.
- Checkpoints conducted under neutral, pre-established guidelines and administrative planning reduce discretion and limit subjective intrusion compared to random stops.
- The Fourth Amendment does not require the government to prove that a checkpoint is the least intrusive or most effective means of addressing the problem; a reasonable advancement of the governmental interest can suffice when intrusion is slight.

## Conclusion

The Court held that Michigan’s sobriety checkpoint program, implemented under structured guidelines and involving brief, uniform stops, constituted reasonable Fourth Amendment seizures when balanced against the State’s strong interest in preventing drunk driving and the program’s limited objective and subjective intrusion on motorists.


Mich. Dep't of State Police v. Sitz, 496 U.S. 444 (1990)