Are DUI checkpoints legal in California?

Yes, when they follow the framework of Ingersoll v. Palmer (1987) 43 Cal.3d 1321: supervisory-level decisions about location and operation, a neutral formula for which cars to stop, visible official markings, brief detentions, and safety precautions. Drivers directed into a checkpoint must stop, and Vehicle Code section 2814.2 makes compliance mandatory.

The California Supreme Court upheld sobriety checkpoints in Ingersoll v. Palmer (1987) 43 Cal.3d 1321 as administrative inspections rather than criminal detentions, but only when run within constitutional guardrails. The factors courts weigh: decision-making by supervisory personnel rather than field officers, a neutral mathematical formula for stopping vehicles, adequate safety measures and lighting, a reasonable location and time, visible indicia of the checkpoint's official nature, minimal detention length, and advance publicity — with later cases treating the factors as a totality rather than a rigid checklist. Vehicle Code section 2814.2 requires drivers to stop and submit to the screening. A driver who lawfully turns off before entering a checkpoint has not, by that act alone, given grounds for a stop, though any observed violation will. When a checkpoint materially departs from the Ingersoll framework, the remedy is a motion to suppress the resulting evidence under Penal Code section 1538.5 — checkpoint records, staffing plans, and operational orders are discoverable and worth examining in any checkpoint arrest.

Authority: Ingersoll v. Palmer (1987) 43 Cal.3d 1321