Memorial Day has come and gone, kicking off the summer holidays. Increased DUI enforcement has become fairly routine during major holidays, and for good reason. One study indicates that Memorial Day is the deadliest holiday weekend to travel.

This often leads to increased DUI patrols and sobriety checkpoints. Despite their popularity, however, some still question the legality of DUI checkpoints.

The history of DUI checkpoints

In the 1970s and ’80s, the law was unclear on sobriety checkpoints. Proponents argued DUI checkpoints would keep people from drinking and driving, especially during holidays when alcohol is often consumed. Critics argued that DUI checkpoints violated drivers’ constitutional rights against unreasonable search and seizure under the Fourth Amendment.

The issue made it all the way to the U.S. Supreme Court. In a landmark 1990 ruling (Michigan Dept. of State Police v. Sitz), the Supreme Court ruled that sobriety checkpoints were constitutional if conducted properly. It left the actual logistics of how and when to conduct checkpoints up to each individual state.

Currently, only 12 states do not conduct DUI checkpoints. Illinois isn’t one of them.

Conducting ‘proper’ sobriety checkpoints

Though legal, police cannot simply stop cars at random and claim they were part of a sobriety checkpoint. Law enforcement agents must follow these guidelines when setting up a DUI checkpoint:

  • Select a proper location that doesn’t create unnecessary traffic jams
  • Warn drivers of an upcoming checkpoint with signs, flares, flags, media announcements or other methods
  • Clearly identify themselves as police by using marked police cars and wearing their uniforms
  • Develop a strategy for which cars to pull over in advance, like pulling over every third car, all the red cars or those drivers who exhibit clear signs of drunkenness
  • Have probable cause before making a DUI arrest

This last point is very important. Even though DUI checkpoints are legal in Illinois, police must still have probable cause to arrest you for drunk driving. So, the same DUI defense strategies as “normal” DUI cases apply to these arrests. If police did not have probable cause or improperly administered sobriety tests at a DUI checkpoint, any charges or penalties you face could be minimized or dropped.