W20-1 Road Work Ahead
Warns approaching drivers that a work operation is taking place on or near the roadway ahead so they can slow down and stay alert for changing conditions.
- Sign Name
- Road Work Ahead
- General Meaning
- Warns approaching drivers that a work operation is taking place on or near the roadway ahead so they can slow down and stay alert for changing conditions.
- MUTCD Code
- W20-1
- Official designation
- Road Work (with distance) — FHWA SHS 2024, App. B5-20
- 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"
Material / Application Notes
Lead advance warning sign on lane and shoulder work setups. 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.
What It Means / When This Sign Is Used
In the field, W20-1 Road Work Ahead is typically positioned at the advance warning area, ahead of the work. Common deployments include lead advance warning sign on lane and shoulder work setups; paired with a distance plaque (e.g. AHEAD or a stated distance); used on streets, highways, and within local agency right-of-way permits. 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 Road Work Ahead sign requirementsWhen & Where It's Used
- Lead advance warning sign on lane and shoulder work setups
- Paired with a distance plaque (e.g. AHEAD or a stated distance)
- Used on streets, highways, and within local agency right-of-way permits
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
Typically the first advance warning sign in a California temporary traffic control zone, placed ahead of the work area at the spacing called for in the CA MUTCD Part 6 and the applicable Standard Plan or project TCP.
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 advance warning placement and spacing match the posted speed and the TCP. Public Ready reviews whether the ROAD WORK AHEAD sign leads the sign sequence correctly for the work type.
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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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