W4-2 Lane Ends Merge Left Sign

Uses a symbol to warn that a travel lane is ending and that traffic must merge in the indicated direction where the roadway narrows.

W4-2 Lane Ends Merge Left signLANE ENDSMERGELEFT
Sign codeW4-2
Federal codeW4-2
NameLane Ends Merge Left
CategoryWarning Signs
ShapeDiamond
ColorOrange background, black symbol (temporary traffic control use)
California statusUsed in California per CA MUTCD
Typical CA minimum size48" × 48" on conventional roads; 60" × 60" on expressways and freeways

What This Sign Means

Uses a symbol to warn that a travel lane is ending and that traffic must merge in the indicated direction where the roadway narrows.

California Temporary Traffic Control Use

Used in California lane-closure tapers to reinforce the merge as a lane drops, supplementing the word-message lane-closure warnings.

Common TCP Context

  • Lane reductions and merging tapers in work zones
  • Supplements W20-5 series lane-closure signs
  • Used where a lane is permanently dropped near work

California Size Requirements

Typical minimum: 48" × 48" on conventional roads; 60" × 60" on expressways and freeways.

Sizes are CA MUTCD minimums and vary by roadway classification and speed. Verify against the CA MUTCD 2026 (CA MUTCD Part 6 (Temporary Traffic Control), Chapter 6F; warning-sign design in Part 2C), Caltrans sign specifications, and the reviewing agency.

Common Placement on a TCP

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.

Los Angeles Area Usage Notes

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

  • Merge direction on the sign does not match the open lane in the field.
  • Taper begins before the lane-closure warning is reached.
  • Sign spacing not adjusted for the posted speed.
  • Wrong size specified for a multilane facility.

Plan Review Notes

Verify the symbol merge direction matches the open lane and taper. Public Ready confirms merge symbols agree with the lane-closure plan.

Signs Commonly Used Together

These signs are typically deployed alongside W4-2 on a California TCP.

Rent or Purchase This Sign

Need a LANE ENDS / merge symbol sign (W4-2)? Public Ready can supply it for your lane-closure setup.

Official References

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.

Related Signs

W9-2 Lane Ends signLANE ENDSWarning Signs
W9-2
Lane Ends
W20-5 Lane Closed Ahead signLANECLOSEDAHEADWarning Signs
W20-5
Lane Closed Ahead
W20-5a Right Lane Closed Ahead signRIGHTLANECLOSEDAHEADWarning Signs
W20-5a
Right Lane Closed Ahead
W20-5b Left Lane Closed Ahead signLEFT LANECLOSEDAHEADWarning Signs
W20-5b
Left Lane Closed Ahead

Need signs for a California project?

Need to rent, purchase, or include traffic control signs on a California project? Public Ready can help with sign rental, purchase, sign packages, TCP sign legends, and permit coordination.