W3-5b VARIABLE SPEED ZONE AHEAD Requirements
Application notes for W3-5b VARIABLE SPEED ZONE AHEAD. The official manual distinguishes mandatory standards, recommended guidance, and optional applications; consult the linked sources for the provisions that apply.
California Application & Variants
Use for a zone where the limit varies with time or conditions. Provide the applicable Speed Limit sign at the beginning of the zone.
1. When VARIABLE SPEED ZONE AHEAD Is Used
Warns of an approaching zone with variable speed limits.
- Roadway geometry and approach-warning review
2. Placement and Application Notes
Position W3-5b in advance of the condition, with placement determined from the approach speed, sight distance, and applicable California manual provisions..
- 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 W3-5b and its orientation to the actual roadway condition.
- Use for a zone where the limit varies with time or conditions. Provide the applicable Speed Limit sign at the beginning of the zone.
- Select size and installation using the applicable California table and responsible agency requirements.
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Verify W3-5b 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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