In 1990, the United States Supreme Court ruled in Michigan v. Sitz that the infringement of Fourth Amendment rights caused by DUI checkpoints is overshadowed by the potential public benefit of getting dangerous, impaired drivers off the road. The court added that DUI checkpoints must follow certain guidelines to be legal:
•Decisions must be made by supervisors, not arresting officers
•Vehicles must be stopped only according to a predetermined formula
•Public and officer safety are most important
•Locations must be selected by policymakers, based on drunk driving statistics
•Duration must be limited by concerns of effectiveness and intrusiveness
•Clearly visible warning lights and signs must be displayed telling drivers
•Drivers must be detained for the minimum amount of time possible
•Advance publication of the place and time is required to increase its deterrent effect and minimize intrusiveness
Even after the United States Supreme Court ruled that DUI checkpoints do not violate the Fourth Amendment, protecting against unduly burdensome and intrusive search and seizure, 12 states continue to prohibit DUI checkpoints. The states are Alaska, Idaho, Iowa, Michigan, Minnesota, Montana, Oregon, Rhode Island, Texas, Washington, Wisconsin, and Wyoming. These states prohibit DUI checkpoints for one of the following reasons: (i) DUI checkpoints are illegal under state law; (ii) law enforcment officers have not been granted authority to administer DUI checkpoints; or (iii) DUI checkpoints have been held to violate the state constitution.