Police set up a highway checkpoint to obtain information from motorists about a hit-and-run accident occurring about one week earlier at the same location and time of night. Officers stopped each vehicle for 10 to 15 seconds, asked the occupants whether they had seen anything happen there the previous weekend, and handed each driver a flyer describing and requesting information about the accident. As respondent Lidster approached, his minivan swerved, nearly hitting an officer. The officer smelled alcohol on Lidster's breath. Another officer administered a sobriety test and then arrested Lidster. He was convicted in Illinois state court of driving under the influence of alcohol. He challenged his arrest and conviction on the ground that the government obtained evidence through use of a checkpoint stop that violated the Fourth Amendment. The trial court rejected that challenge, but the state appellate court reversed. The State Supreme Court agreed, holding that, in light of Indianapolis v. Edmond,531 U. S. 32, the stop was unconstitutional.
Held: The checkpoint stop did not violate the Fourth Amendment. Pp. 2-8.
(a) Edmond does not govern the outcome of this case. In Edmond, this Court held that, absent special circumstances, the Fourth Amendment forbids police to make stops without individualized suspicion at a checkpoint set up primarily for general "crime control" purposes. 531 U. S., at 41, 44. Specifically, the checkpoint in Edmond was designed to ferret out drug crimes committed by the motorists themselves. Here, the stop's primary law enforcement purpose was not to determine whether a vehicle's occupants were committing a crime, but to ask the occupants, as members of the public, for help in providing information about a crime in all likelihood committed by others. Edmond's language, as well as its context, makes clear that an information-seeking stop's constitutionality was not then before this Court. Pp. 2-4.
(b) Nor does the Fourth Amendment require courts to apply an Edmond-type rule of automatic unconstitutionality to such stops. The fact that they normally lack individualized suspicion cannot by itself determine the constitutional outcome, as the Fourth Amendment does not treat a motorist's car as his castle, see, e.g., New York v. Class,475 U. S. 106, 112-113, and special law enforcement concerns will sometimes justify highway stops without individualized suspicion, see, e.g., Michigan Dept. of State Police v. Sitz,496 U. S. 444. More-over, the context here (seeking information from the public) is one in which, by definition, the concept of individualized suspicion has little role to play, and an information-seeking stop is not the kind of event that involves suspicion, or lack thereof, of the relevant individual. In addition, information-seeking highway stops are less likely to provoke anxiety or to prove intrusive, since they are likely brief, the questions asked are not designed to elicit self-incriminating information, and citizens will often react positively when police ask for help. The law also ordinarily permits police to seek the public's voluntary cooperation in a criminal investigation. That the importance of soliciting the public's assistance is offset to some degree by the need to stop a motorist--
which amounts to a "seizure" in Fourth Amendment terms, e.g., Edmond, supra, at 40--is not important enough to justify an Edmond-type rule here. Finally, such a rule is not needed to prevent an unreasonable proliferation of police checkpoints. Practical considerations of limited police resources and community hostility to traffic tie-ups seem likely to inhibit any such proliferation, and the Fourth Amendment's normal insistence that the stop be reasonable in context will still provide an important legal limitation on checkpoint use. Pp. 4-6.
(c) The checkpoint stop was constitutional. In judging its reasonableness, hence, its constitutionality, this Court looks to "the gravity of the public concerns served by the seizure, the degree to which the seizure advances the public interest, and the severity of the interference with individual liberty." Brown v. Texas,443 U. S. 47, 51. The relevant public concern was grave, as the police were investigating a crime that had resulted in a human death, and the stop advanced this concern to a significant degree given its timing and location. Most importantly, the stops interfered only minimally with liberty of the sort the Fourth Amendment seeks to protect. Viewed objectively, each stop required only a brief wait in line and contact with police for only a few seconds. Viewed subjectively, the systematic contact provided little reason for anxiety or alarm, and there is no allegation that the police acted in a discriminatory or otherwise unlawful manner. Pp. 6-8.
202 Ill. 2d 1, 779 N. E. 2d 855, reversed.
Breyer, J., delivered the opinion of the Court, in which Rehnquist, C. J., and O'Connor, Scalia, Kennedy, and Thomas, JJ., joined, and in which Stevens, Souter, and Ginsburg, JJ., joined as to Parts I and II. Stevens, J., filed an opinion concurring in part and dissenting in part, in which Souter and Ginsburg, JJ., joined.