The flyers essentially apply general principals of U.S. Constitutional protections. The general idea behind the flyer is to display it through a car window and not to establish eye contact with the police, asserting Constitutional rights in an effort to limit the time and interaction with the police at the DUI checkpoint. Police may try to argue that they had reasonable suspicion in some way, to move forward with routine questioning.
For instance, if you are stopped at a DUI checkpoint and have a problem with your vehicle, license or registration, the police may question you. During questioning, they may assert that you have symptoms of intoxication, giving them authority to conduct a DUI investigation. Typical DUI symptoms can be bloodshot, watery eyes or the smell of an alcoholic beverage on your breath. Generally speaking, if you are argumentative or hostile during a routine traffic stop, the police may find reasons to detain or arrest you.
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