Warns that work is taking place on the shoulder ahead, alerting drivers to workers and equipment near the edge of the traveled way.
MUTCD-style sign reference illustration. Always verify against the official CA MUTCD and Caltrans sign charts.
| Sign code | W21-5 |
|---|---|
| Federal code | W21-5 |
| Name | Shoulder Work |
| Category | Warning Signs |
| Shape | Diamond |
| Color | Orange background, black legend |
| California status | Used in California per CA MUTCD |
| Typical CA minimum size | 48" × 48" on conventional roads; 60" × 60" on expressways and freeways |
Download this sign or open the official MUTCD reference.
Official source: FHWA Standard Highway Signs, 2024 (11th Edition) — Warning & Temporary Traffic Control signs.
Source: FHWA Standard Highway Signs — Public Domain. California: CA MUTCD 2026 (effective Jan 18, 2026).
Files linked from FHWA are official government publications in the public domain. CA MUTCD and Caltrans links open official government websites. Always verify against the current edition.
Warns that work is taking place on the shoulder ahead, alerting drivers to workers and equipment near the edge of the traveled way.
Warns that work is taking place on the shoulder ahead, alerting drivers to workers and equipment near the edge of the traveled way. In the field, W21-5 Shoulder Work is typically positioned at the approach to the activity area. Common deployments include shoulder repairs, striping, and maintenance; operations that keep travel lanes open; paired with channelizing devices along the shoulder. Always confirm its size, retroreflective sheeting, spacing, and placement against the CA MUTCD 2026 and the reviewing agency before finalizing the traffic control plan.
Used on California highways and streets for shoulder operations that do not close a travel lane but place workers and equipment on the shoulder.
Common field deployments
Agency review note
StreetsLA, LA County DPW, and Caltrans District 7 may require larger sizes or additional devices. Verify with the reviewing agency before finalizing the TCP.
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.
Where it sits: Approach to the activity area.
CA MUTCD reference: CA MUTCD Part 6 (Temporary Traffic Control), Chapter 6F; warning-sign design in Part 2C.
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.
Confirm shoulder buffer and device placement protect the work area without intruding on the travel lane. Public Ready reviews shoulder setups.
These signs are typically deployed alongside W21-5 on a California TCP.
Working on the shoulder? Public Ready can supply SHOULDER WORK (W21-5) and edge-of-roadway devices.
Free official resource — opens official government website
Free official resource — opens official government website
Free official resource — opens official government website
Free official resource — opens official government website
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.
To understand the bigger picture around permits, agency review, lane closures, and pedestrian access for work zones using W21-5 Shoulder Work, visit WorkZoneCompliance.com.
Public Ready can help with W21-5 Shoulder Work — including sign rental or purchase, work-zone signs, TCP sign legends, and permit coordination, and agency-review support for Caltrans District 7, the City of Los Angeles, and LA County.
