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W8-24 Steel Plate Ahead

Warns that steel plates (trench plates) are in place on the roadway ahead, alerting drivers to the change in surface and possible bump.

Sign Name
Steel Plate Ahead
General Meaning
Warns that steel plates (trench plates) are in place on the roadway ahead, alerting drivers to the change in surface and possible bump.
MUTCD Code
W8-24
Typical Use
Advance warning area, ahead of the work.
Sign Category
Warning Signs

Specifications

Standard Shape
Diamond
Background Color
Orange
Legend / Symbol
Black legend
Border
Black
Reflectivity
High Intensity (for nighttime visibility)
Compliance
MUTCD / CA MUTCD

Standard Sizes (inches)

  • 30 in Diamond30" × 30"
  • 36 in Diamond36" × 36"
  • 48 in Diamond48" × 48"
  • 60 in Diamond60" × 60"
View all standard sizes and options

Material / Application Notes

Utility and street-cut work with trench plates. Confirm placement and supplemental plaques against the applicable CA MUTCD standard.

View this sign on the Federal MUTCD (FHWA)

California Notes

California-specific application notes and adoptions may differ. Review California requirements where applicable.

Go to California Notes
W8-24 Steel Plate Ahead — official FHWA layout

What It Means / When This Sign Is Used

In the field, W8-24 Steel Plate Ahead is typically positioned at the advance warning area, ahead of the work. Common deployments include utility and street-cut work with trench plates; overnight/weekend plated excavations in the traveled way; used where plates create a surface change or bump. Always confirm its size, retroreflective sheeting, spacing, and placement against the CA MUTCD 2026 and the reviewing agency before finalizing the traffic control plan.

Learn more about Steel Plate Ahead sign requirements

When & Where It's Used

  • Utility and street-cut work with trench plates
  • Overnight/weekend plated excavations in the traveled way
  • Used where plates create a surface change or bump

Placement on a Traffic Control Plan

Where it sits
Advance warning area, ahead of the work.
CA MUTCD reference
CA MUTCD Part 6 (Temporary Traffic Control), Chapter 6F; warning-sign design in Part 2C
Typical minimum size
48" × 48" on conventional roads; 60" × 60" on expressways and freeways

California / Field Use Notes

Commonly used in California utility and street-cut work where steel trench plates cover an excavation in the traveled way between work shifts.

In Los Angeles, this sign must conform to CA MUTCD 2026. Work in City of LA right-of-way is reviewed by StreetsLA and the Bureau of Engineering (BOE); state highways in LA County are permitted and reviewed by Caltrans District 7; county roads are permitted by LA County DPW. Sizes, retroreflectivity, and placement must meet CA MUTCD minimums — local agencies may require larger signs based on roadway class, speed, pedestrian volume, and proximity to schools or transit.

Common Plan Review Comments

  • Sign not shown at the correct advance distance for the posted speed.
  • Advance warning sign missing or out of sequence on the TCP.
  • Wrong size specified for the roadway classification (conventional vs. expressway).
  • Sign sheeting / retroreflectivity class not noted on the plan.

Confirm plates are secured, ramped/beveled as required, and signed. Public Ready reviews steel-plate signing and treatment.

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. Written against California MUTCD 2026 (effective January 18, 2026) and the Federal MUTCD 11th Edition. Official sources last verified June 2026.

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