Checkpoints (Roadblocks)

If police set up a checkpoint (also known as a roadblock) on the highway, requiring all drivers to stop and answer some questions, is that constitutional? The answer is yes if certain conditions are met.

To assess the constitutionality of police conduct, traditional Fourth Amendment analysis provides that the police cannot search a person unless they have both probable cause to believe evidence of crime is located with that person and a warrant authorizing the search. Since the 1960s, however, two lines of cases deviating from this traditional approach have developed to give law enforcement more flexibility. One is stop and frisk law. The other is a series of cases referred to as ‘‘special needs’’ cases. The Fourth Amendment analysis developed in these ‘‘special needs’’ cases governs the constitutionality of highway checkpoints.

The types of cases referred to as ‘‘special needs’’ cases today were originally described as administrative inspection cases. These cases generally involved police activity that focused on goals other than the traditional investigation of crime. Examples include government agents conducting workplace inspections for compliance with occupational health and safety laws and government agents inspecting housing for compliance with local codes. In these cases, police were not required to meet the usual probable cause and warrant requirements. Rather, the Fourth Amendment requirements were relaxed, so that warrants were frequently not required, and the grounds necessary to justify the police conduct were reduced from probable cause to a lesser standard, reasonable suspicion, or eliminated altogether. The Supreme Court defined the reasonableness of government conduct in these cases by using a balancing analysis, balancing the government’s need to search against the extent of the invasion to the citizen. One line of cases in this category is the roadblock cases.

The question of whether roadblocks are constitutional was first raised in the mid-1970s in cases where the police stopped cars near the border looking for illegal aliens. After concluding that police could search the cars only with probable cause, the Court authorized police to stop the cars and briefly question the occupants. If the stops were roving stops, that is, if the police were driving around to select which cars to stop, the police had to justify the stop and questioning by showing reasonable suspicion that led them to that car. This was the holding of United States v. Brignoni-Ponce. On the other hand, if the stops were fixed checkpoint stops, police could briefly question car occupants with no grounds whatsoever. The distinction was based on the idea that a fixed checkpoint necessarily limits police discretion, because they cannot pick the cars they stop, they have to take what comes their way. This limit on discretion minimizes the chance of abuse. In contrast, a roving stop allows police to cruise around and select which cars they approach, so in that situation, police have to provide reasons for stopping the cars they did. In combination, these cases indicated that whether grounds were required to stop a car depended to two variables: the intrusiveness of the police activity (search of the car as opposed to brief questioning of the occupants) and the amount of police discretion used (fixed checkpoints as opposed to roving stops).

The law was eventually refined in other types of investigations. When the police in Delaware made roving stops of cars for license and registration checks, and they made the stops randomly—that is, with no grounds to justify why the particular cars were chosen—the Supreme Court in Delaware v. Prouse declared it unconstitutional. But in a significant case decided in 1990, the Supreme Court found it constitutional when Michigan used checkpoint stops to look for persons driving under the influence of alcohol. The Michigan authorities had no grounds for stopping the particular cars, but because their discretion was limited by the fixed character of the checkpoint, the Court approved it. And, the Supreme Court relied on the fact that the purpose of the checkpoint was not so much to investigate crime but to work toward the goal of highway safety. The highway death toll from drunk drivers indicated a special need for police to make the highways safer.

Two more Supreme Court cases complete the law on roadblocks. In 2000, the city of Indianapolis set up fixed checkpoints to briefly question occupants of cars about possession of street drugs. Police articulated no grounds for stopping the cars. In addition, the police had drug-detection dogs present at the roadblock to sniff the cars. The Court held this practice to be unconstitutional on the basis that the primary purpose was to detect evidence of ordinary criminal wrongdoing, so the case fell outside of the special needs category, and the checkpoint stops with no grounds were struck down. Most recently, in 2004, the Court held that a checkpoint set up to question car occupants about a recent hit-and-run case was constitutional. Like the drug checkpoint struck down, the police questioned each car without having any grounds for picking that car. However, the Court determined that asking for information about a recent hit-and-run did qualify as a special need situation, and the checkpoint was not set up merely to do the usual criminal investigation. Thus the checkpoint was constitutional.

In summary, the law today is that under the Fourth Amendment, police can use fixed checkpoints or roadblocks to briefly question occupants of the stopped cars without articulating any individualized reason for stopping that car, if the police purpose is focused on a special need rather than the traditional purpose of detecting evidence of crime. This is significant, because traditional Fourth Amendment law would not allow police to stop or question persons without articulating individualized grounds for selecting that person. However, based on the evolution described previously, the Supreme Court has now authorized police to use roadblocks under the conditions described.

SARAH N. WELLING

Cases and Statutes Cited

• Camara v. Municipal Court, 387 U.S. 523 (1967) 
• City of Indianapolis v. Edmond, 531 U.S. 32 (2001) 
• Delaware v. Prouse, 440 US. 648 (1979) 
• Fourth Amendment 
• Illinois v. Lidster, 540 U.S. 419 (2004) 
• Marshall v. Barlow’s, Inc., 436 U.S. 307 (1978) 
• Michigan Department of State Police v. Sitz, 496 U.S. 444 (1990) 
• U.S. v. Brignoni-Ponce, 422 U.S. 873 (1975) 

See also Delaware v. Prouse, 440 US. 648 (1979); Search (General Definition); Seizures; United States v. Brignoni-Ponce, 422 U.S. 873 (1975)