(Page 4 of 4)

U.S. Supreme Court

Id. at 663, n. 26 .

Unlike Prouse, this case involves neither a complete absence of empirical data nor a challenge to random highway stops. During the operation of the Saginaw County checkpoint, the detention of each of the 126 vehicles that entered the checkpoint resulted in the arrest of two drunken drivers. [p*455] Stated as a percentage, approximately 1.5 percent of the drivers passing through the checkpoint were arrested for alcohol impairment. In addition, an expert witness testified at the trial that experience in other States demonstrated that, on the whole, sobriety checkpoints resulted in drunken driving arrests of around 1 percent of all motorists stopped. 170 Mich.App. at 441, 429 N.W.2d at 183. By way of comparison, the record from one of the consolidated cases in Martinez-Fuerte showed that, in the associated checkpoint, illegal aliens were found in only 0.12 percent of the vehicles passing through the checkpoint. See 428 U.S. at 554. The ratio of illegal aliens detected to vehicles stopped (considering that on occasion two or more illegal aliens were found in a single vehicle) was approximately 0.5 percent. See Ibid. We concluded that this "record . . . provides a rather complete picture of the effectiveness of the San Clemente checkpoint", ibid,, and we sustained its constitutionality. We see no justification for a different conclusion here.

In sum, the balance of the State's interest in preventing drunken driving, the extent to which this system can reasonably be said to advance that interest, and the degree of intrusion upon individual motorists who are briefly stopped, weighs in favor of the state program. We therefore hold that it is consistent with the Fourth Amendment. The judgment of the Michigan Court of Appeals is accordingly reversed, and the cause is remanded for further proceedings not inconsistent with this opinion.

It is so ordered.


* Statistical evidence incorporated in the dissent suggests that this figure declined between 1982 and 1988. See post at 460-461 n. 2 and 467-468 , n. 7 (citing National Highway Traffic Safety Administration, Fatal Accident Reporting System 1988). It was during this same period that police departments experimented with sobriety checkpoint systems. Petitioners, for instance, operated their checkpoint in May, 1986, see App. to Pet. for Cert. 6a, and the Maryland State Police checkpoint program, about which much testimony was given before the trial court, began in December, 1982. See id. at 84a. Indeed, it is quite possible that jurisdictions which have recently decided to implement sobriety checkpoint systems have relied on such data from the 1980s in assessing the likely utility of such checkpoints.