This guide summarizes the MUTCD requirements and practical application guidance for the W4-2L LEFT LANE ENDS sign. Use this resource to understand when it is required, how to place it correctly, and how to maintain clear visibility for safe operations.
Left-lane reductions and merging tapers in work zones
Advance warning area, ahead of the work.
Mount at the standard height and setback for the roadway with clear sight lines.
High reflectivity and clear sight lines are essential day and night.
Warns that the left travel lane ends ahead and that traffic in the left lane must merge into the adjacent lane where the roadway narrows.
Warns that the left travel lane ends ahead and that traffic in the left lane must merge into the adjacent lane where the roadway narrows. In the field, W4-2L Left Lane Ends is typically positioned at the advance warning area, ahead of the work. Common deployments include left-lane reductions and merging tapers in work zones; supplements W20-5 series lane-closure signs where the left lane closes; used where the left lane is permanently dropped near work. Always confirm its size, retroreflective sheeting, spacing, and placement against the CA MUTCD 2026 and the reviewing agency before finalizing the traffic control plan.
Advance warning area, ahead of the work.
Typical minimum: 48" × 48" on conventional roads; 60" × 60" on expressways and freeways.
Used in California lane-closure tapers when the left lane is dropped, reinforcing the merge as the left lane ends and supplementing the word-message lane-closure warnings.
Go to California NotesEducational 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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