Which of the following is NOT a condition for legal DWI checkpoints?

The choice indicating that no advance publicity is provided is the correct answer because legal DWI checkpoints typically require some level of advance notice to the public to meet legal standards and ensure transparency. Public notification is a crucial aspect as it helps to inform drivers about the checkpoint's existence, promoting safety and compliance with the law.

In addition, official scheduling by a supervisory officer, equal treatment of all vehicles, and public notice provided to residents are all conditions that must be met for a DWI checkpoint to be considered legal. These requirements help ensure that checkpoints are conducted in an organized, fair, and effective manner. Proper scheduling helps in avoiding arbitrary enforcement, while equal treatment ensures that no specific group of drivers is unfairly targeted. Public notice aids in maintaining the credibility and integrity of law enforcement practices.