People may have heard that a police officer has to have probable cause before he or she can pull the car over to find out if the driver is driving under the influence.
If this is true, then how can it be legal for law enforcement to set up roadblocks and stop drivers specifically for this purpose?
The Supreme Court ruling
According to Cornell Law School’s Legal Information Institute, the U.S. Supreme Court weighed in on whether DUI checkpoints violate the Fourth Amendment. Here is what the Chief Justice said.
First, the Court verified that such stops do count as a “seizure” under the Fourth Amendment. The next step was determining whether this type of seizure is reasonable.
The Justices determined that the seizure’s reasonableness does not come from probable cause. Instead, it comes from the significance of the matter to the country as a whole, the extent to which it furthers the public interest and the degree to which it interferes with individual liberties. In short, the Justices ruled that the benefits outweighed the intrusion.
According to the Centers for Disease Control and Prevention, drivers should note that safety experts do not measure the effectiveness of a checkpoint by the number of DUI arrests the officers make at any given stop. The goal of the checkpoint is not to make arrests; it is to deter drunk driving. A more effective measurement may be the number of vehicles that officers evaluate at the checkpoint.
With that in mind, the National Highway Traffic Safety Association notes that law enforcement should publicize checkpoints and ensure that they are visible. Authorities typically post the locations, dates and times online, and may also advertise this information in a local newspaper.