C23(CA) · Road / Ramp Work Ahead
C23(CA) Sizes & Dimensions
These are dimensions shown on the linked layout. Select the required size using the applicable MUTCD and agency requirements; the smallest drawing size is not necessarily the permitted minimum. All dimensions below are in inches.
Open C23(CA) Official Dimension Drawing (PDF, opens in a new tab)Official PDF · Opens in a new tab
Dimensions from the Official Drawing
Dimensions are side lengths of the diamond, not its corner-to-corner span.
- Layout 130" × 30"
See layout variant and applicable MUTCD size-selection requirements.
Dimensions are side lengths of the diamond, not its corner-to-corner span.
- Layout 248" × 48"
See layout variant and applicable MUTCD size-selection requirements.
Dimensions are side lengths of the diamond, not its corner-to-corner span.
Drawing dimensions are not a universal minimum or an agency approval. These are dimensions shown on the linked layout. Select the required size using the applicable MUTCD and agency requirements; the smallest drawing size is not necessarily the permitted minimum.
California Application & Variants
The older Caltrans C23(CA) drawing shows ROAD WORK AHEAD and permits RAMP as the first line. Current CA MUTCD 2026 Section 6H.03 identifies RAMP WORK AHEAD as C23(CA), which may substitute for W20-1 where applicable. W20-1 is the ROAD (STREET) WORK sign. The illustrated ROAD legend and the current California ramp application must be read in that context.
Permitted messages
- ROAD WORK AHEAD
- RAMP WORK AHEAD
Size selection: The linked older drawing shows 30 × 30 and 48 × 48 inches. Current Table 6H-1(CA) lists 36 × 36 inches for the conventional-road minimum and 48 × 48 inches for expressways/freeways. Drawing dimensions alone do not establish the required installation size.
Official References
- C23(CA) — Caltrans specification drawing (opens in a new tab)
- C23(CA) — CA MUTCD 2026 Chapter 6H — TTC Zone Warning Signs, PDF page 2 (opens in a new tab)
- California MUTCD (Caltrans) (opens in a new tab)
- Federal MUTCD — 11th Edition (FHWA) (opens in a new tab)
- Caltrans Sign Charts (opens in a new tab)
- FHWA Standard Highway Signs (opens in a new tab)
Educational 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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