In a widely-criticized 5-4 decision, the United States Supreme Court in Michigan vs Sitz decided some years ago that DUI sobriety checkpoints (aka "DUI roadblocks) did not violate the search-and-seizure provisions of the Fourth Amendment of the U.S. Constitution. See my post Are DUI Roadblocks Constitutional?.
However, it is not illegal to detect and avoid DUI sobriety checkpoints. And, in fact, the court in Sitz indicated that there were restraints on law enforcement in planning, setting up and administering these sobriety checkpoints. These restraints were left up to the individual states to determine, but most have adopted guidelines similar to those recommended by the California Supreme Court in Ingersoll vs Palmer. Among these are that the checkpoints must be publicized to minimize intrusiveness.
A further requirement, the Court in Ingersoll said, is that “A sign announcing the checkpoint was posted sufficiently in advance of the checkpoint location to permit motorists to turn aside, and under the operational guidelines no motorist was to be stopped merely for choosing to avoid the checkpoint.” See Turning Away from a California DUI Sobriety Checkpoint. Of course, the police will be suspicious of anyone attempting to avoid a DUI sobriety checkpoint — and will commonly try to find some justification for stopping them, such as the driver making an illegal U-turn or having defective brake lights.
The best course of action: since the sobriety checkpoints must be previously publicized, find out where and when any DUI checkpoints in your area are going to be set up — and avoid them. Unfortunately, the police usually choose to "publicize" them in a tiny notice in the back pages of a minor newspaper.
So how can you locate planned DUI sobriety checkpoints in your area?
Simple: Visit the sobriety checkpoint page on my DUI defense law firm’s website: Sobriety Checkpoints: Laws and Locations. Understandably, the focus is on sobriety checkpoints located in California, but there is also information on access to the locations of checkpoints nationwide.