Michigan State Police vs. Sitz case established the Balancing Test for DUI Roadblocks. In that case the Supreme Court applied a balancing test developed when considering the legality of DUI roadblocks. That balance is of three factors:
- Public concern served by the seizures;
- How much the seizure advances that public interest; and
- How severe the roadblock invades your personal rights.
Michigan State Police vs. Sitz
First, for DUI Roadblocks, the obvious public concern is drunk driving. In Sitz, the Supreme Court found this concern to be as real as can be, noting that drunk driving occurs, sadly, often.
Next, the Supreme Court tried to gauge the effectiveness of these roadblocks. They found that DUI checkpoints found drunk drivers about 1.5% of the time, which the Court as a reasonable advancement of public interest.
Lastly, the severity of the invasion on your rights. The courts break this down in two ways: objective intrusion and subjective intrusion. First, objective intrusions are the superficial factors like the total time of the stop. In Sitz, the total stop was 25 seconds and only a few questions were asked. Next, subjective intrusion is how much the roadblock disturbs an average, innocent driver. So, DUI roadblocks must be well marked and have advanced warning. So, with all of these factors in the balance, the United State Supreme Court has ruled DUI roadblocks to be constitutional.
Additional State Factors
Additionally, states have called out more factors not addressed in the Sitz case, such as a heavier emphasis on the discretion of the police working the checkpoint, the location of the checkpoint, whether or not there are better alternatives to a checkpoint, and others.