This guide summarizes the MUTCD requirements and practical application guidance for the W6-4 NARROW TWO-WAY TRAFFIC sign. Use this resource to understand when it is required, how to place it correctly, and how to maintain clear visibility for safe operations.
Approach to a narrow two-way, two-lane operation around a work area
On the approach to a narrow section that carries two-way traffic (for example a two-lane, two-way operation set up around the work area).
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.
The W6-4 Narrow Two-Way Traffic sign warns that the roadway ahead narrows to a two-way, two-lane operation with opposing traffic on the other side of the center line. The two opposing arrows indicate traffic moving in both directions past the sign. In temporary traffic control it is shown on an orange background, commonly where a lane closure or crossover sets up a narrow two-way section.
The W6-4 Narrow Two-Way Traffic sign warns that the roadway ahead narrows to a two-way, two-lane operation with opposing traffic on the other side of the center line. The two opposing arrows indicate traffic moving in both directions past the sign. In temporary traffic control it is shown on an orange background, commonly where a lane closure or crossover sets up a narrow two-way section. In the field, W6-4 Narrow Two-Way Traffic is typically positioned at the on the approach to a narrow section that carries two-way traffic (for example a two-lane, two-way operation set up around the work area). Common deployments include approach to a narrow two-way, two-lane operation around a work area; used where a lane closure or crossover creates a two-way section; sized and placed per the CA MUTCD and the roadway type. Always confirm its size, retroreflective sheeting, spacing, and placement against the CA MUTCD 2026 and the reviewing agency before finalizing the traffic control plan.
On the approach to a narrow section that carries two-way traffic (for example a two-lane, two-way operation set up around the work area).
Typical minimum: 30" × 36"; 36" × 48" on higher-speed roadways.
W6-4 Narrow Two-Way Traffic is used in California per the CA MUTCD to warn drivers of a narrow two-way operation set up around a work area. Confirm its size, retroreflective sheeting, placement, and spacing against the CA MUTCD 2026 and the reviewing agency before finalizing the traffic control plan.
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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