W4-1 Merge
Uses a symbol to warn that two lanes of traffic are merging into one, alerting drivers in both lanes to yield and merge safely.
- Sign Name
- Merge
- General Meaning
- Uses a symbol to warn that two lanes of traffic are merging into one, alerting drivers in both lanes to yield and merge safely.
- MUTCD Code
- W4-1
- 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
Contraflow and crossover merge points. 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, W4-1 Merge is typically positioned at the advance warning area, ahead of the work. Common deployments include contraflow and crossover merge points; two-to-one tapers where both lanes carry traffic; lane drop approaches in active construction. 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 Merge sign requirementsWhen & Where It's Used
- Contraflow and crossover merge points
- Two-to-one tapers where both lanes carry traffic
- Lane drop approaches in active construction
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
Used in California work zones at points where two moving lanes of traffic converge — such as a contraflow merge point, a temporary crossover merge, or a two-to-one taper where both lanes are live.
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 the merge configuration, taper geometry, and that the symbol correctly represents the merge direction. Public Ready reviews merge signing and taper design.
Related Signs
View All W-Series Signs
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.
Need to Rent or Purchase This Sign? Contact Public Ready.
Public Ready supports sign selection, project-ready sign packages, and equipment sourcing through qualified providers — with expert support built for compliance.