R4-12 SLOW VEHICLES WITH 5 OR MORE FOLLOWING VEHICLES MUST USE TURN-OUT Requirements
Application notes for R4-12 SLOW VEHICLES WITH 5 OR MORE FOLLOWING VEHICLES MUST USE TURN-OUT. The official manual distinguishes mandatory standards, recommended guidance, and optional applications; consult the linked sources for the provisions that apply.
California Application & Variants
California specifies five following vehicles and placement in advance of the first turn-out area. It is not intended in advance of every individual turn-out.
1. When SLOW VEHICLES WITH 5 OR MORE FOLLOWING VEHICLES MUST USE TURN-OUT Is Used
Tells slow-moving drivers with five or more following vehicles to use the turn-out.
- Regulatory signing review
2. Placement and Application Notes
Position R4-12 california specifies five following vehicles and placement in advance of the first turn-out area. It is not intended in advance of every individual turn-out..
- 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: 42" × 24"; 72" × 42". 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 R4-12 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 R4-12 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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