Few things can ruin an otherwise epic night on the town faster than seeing flashing lights in your rear-view mirror. After all, a DUI arrest can cost you a considerable amount. While roadside stops are a common way to catch drunk drivers, officers in Pennsylvania also occasionally set up sobriety checkpoints.

Sobriety checkpoints are a marginally effective enforcement tool. Still, officers must follow strict guidelines when planning and erecting checkpoints. Here are four requirements for a legal sobriety checkpoint in Pennsylvania: 

1. Placement 

Law enforcement administrators, not regular patrol officers, should determine when and where to place a sobriety checkpoint. When deciding to erect one, administrators must choose a location that has a history of DUI arrests. They should also conduct the checkpoint at a time when DUI arrests usually occur. Holidays, popular drinking days and weekends are common times for sobriety checkpoints in the Keystone state.

2. Warning 

Officers cannot trick motorists into driving into sobriety checkpoints. Instead, they must provide advance notice of the checkpoint’s location and time. This notice does not have to be impossible to ignore, though. Publishing information about the checkpoint online or in the newspaper is usually sufficient.

3. Consistency 

At most sobriety checkpoints, officers do not stop every approaching vehicle. Doing so may cause a traffic jam or other problems. Still, officers must have a consistent method for deciding which vehicles to stop. That is, that method may not be either arbitrary or discriminatory.

4. Staffing 

During a sobriety checkpoint, officers should only detain motorists long enough to determine if they may have a blood alcohol concentration level above the 0.08% legal limit. When doing so, they watch for alcohol odors, glassy eyes, slurred speech and other indicators of intoxication. They should not, however, overly inconvenience motorists. Therefore, there should be enough staff at the checkpoint to conduct it in a reasonable, fair, safe and efficient way.

If officers do not conduct a sobriety checkpoint legally, you may be able to suppress the evidence they uncover. As such, if you are facing DUI charges, understanding what constitutes a legal checkpoint is essential.