Can police wait for my patrons to leave my bar to stop them?

This is a typical tactic and there is nothing illegal about it provided that the cops only stop those who appear to be impaired.

No, the police can stop citizens that are breaking the law whereever they are found. If it happens to be outside your bar with some regularity you might ask your staff if your staff has a habit of overserving such patrons. Just a thought. Good luck to you. NOTE: This answer is made available by the lawyer for educational purposes only. By using or participating in this site you understand that there is no attorney client privilege between you and the attorney responding. This site should not be used as a substitute for competent legal advice from a licensed professional attorney with whom you have established an attorney client relationship and all the privileges that relationship provides. The law changes frequently and varies from jurisdiction to jurisdiction. The information and materials provided are general in nature, and may not apply to a specific factual or legal circumstance described in the question.