W21-7 UTILITY WORK AHEAD Requirements
Application notes for W21-7 UTILITY WORK AHEAD. The official manual distinguishes mandatory standards, recommended guidance, and optional applications; consult the linked sources for the provisions that apply.
1. When UTILITY WORK AHEAD Is Used
Warns that utility work is taking place on or near the roadway ahead, alerting drivers to utility crews, equipment, and possible lane or shoulder impacts.
- Utility maintenance and installation in the right-of-way
- Short-duration and mobile utility operations
- Encroachment-permit work for utility agencies
2. Placement and Application Notes
Position W21-7 advance warning area, ahead of the work.
- Place the sign where the intended road users have a clear, unobstructed view on approach.
- Use the mounting height and lateral placement specified for the sign and installation type.
- Use sign assemblies and supplemental plaques only as provided in the applicable manual and approved design.
3. Layout Sizes and Visibility Considerations
Linked-layout dimensions: 30" × 30"; 36" × 36"; 48" × 48". Check the applicable MUTCD and agency requirements for the required installation size.
- Choose size based on roadway speed, sight distance, and mounting location.
- Use the visibility and material requirements specified for this sign and installation.
4. Sign Selection Checks
- Match W21-7 and its displayed legend to the intended condition.
- Check the source drawing for the required directional or message variant.
Related Resources
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Verify W21-7 Requirements
This is an educational reference. Verify sign use, size, placement, and application against the current CA MUTCD, Caltrans sign specifications, Standard Plans, and the reviewing agency. Official source links are gathered in one place.
View official sourcesEducational 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. Reference editions: California MUTCD 2026 (effective January 18, 2026) and the Federal MUTCD 11th Edition with Revision 1.
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