Requires drivers in this lane or approach to proceed straight through the intersection only, prohibiting turning movements.
Requiring through movement at work-zone approaches. Confirm placement and supplemental plaques against the applicable CA MUTCD standard.
View this sign on the Federal MUTCD (FHWA)California-specific application notes and adoptions may differ. Review California requirements where applicable.
Requires drivers in this lane or approach to proceed straight through the intersection only, prohibiting turning movements.
Requires drivers in this lane or approach to proceed straight through the intersection only, prohibiting turning movements. In the field, R3-5a Through Only is typically positioned at the advance warning area, ahead of the work. Common deployments include requiring through movement at work-zone approaches; restricting turns during construction lane-use control; lane-use control where only straight-through travel is permitted. Always confirm its size, retroreflective sheeting, spacing, and placement against the CA MUTCD 2026 and the reviewing agency before finalizing the traffic control plan.
Learn more about Through Only sign requirementsUsed in California work zones where turning movements must be prohibited from an approach, requiring all traffic in the lane to continue straight through.
In Los Angeles, temporary regulatory changes (speed, one-way, turn or entry restrictions) generally involve LADOT review, and on state highways Caltrans District 7. Regulatory authority cannot be created by signing alone — confirm the change is authorized by the agency with jurisdiction over the roadway.
Confirm that the mandatory through movement is consistent with the temporary lane configuration and is properly authorized. Public Ready reviews lane-use control signing.
Educational reference only. This is not an official Caltrans, FHWA, or local agency publication and is not legal or engineering advice. Always verify sign selection, size, placement, spacing, and application against the current CA MUTCD 2026, Caltrans sign specifications, Standard Plans, project documents, and the reviewing agency’s requirements. Local jurisdictions may impose additional requirements, and final selection, placement, and dimensions may require engineering judgment or agency approval. Written against California MUTCD 2026 (effective January 18, 2026) and the Federal MUTCD 11th Edition. Official sources last verified June 2026.
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