
This guide summarizes the MUTCD requirements and practical application guidance for the W21-1 WORKERS sign. Use this resource to understand when it is required, how to place it correctly, and how to maintain clear visibility for safe operations.
Active work areas with workers on foot near traffic
Approach to the activity 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.
Uses a worker symbol to warn that workers are present on or near the roadway ahead, signaling drivers to reduce speed and increase caution.
Uses a worker symbol to warn that workers are present on or near the roadway ahead, signaling drivers to reduce speed and increase caution. In the field, W21-1 Workers is typically positioned at the approach to the activity area. Common deployments include active work areas with workers on foot near traffic; short-duration and mobile operations; supplements lead advance warning signing. Always confirm its size, retroreflective sheeting, spacing, and placement against the CA MUTCD 2026 and the reviewing agency before finalizing the traffic control plan.
Approach to the activity area.
Typical minimum: 48" × 48" on conventional roads; 60" × 60" on expressways and freeways.
Used in California work zones where workers are on foot near live traffic, often supplementing ROAD WORK AHEAD where worker exposure is a concern.
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.
Public Ready supports sign selection, project-ready sign packages, and equipment sourcing through qualified providers — with expert support built for compliance.