MUTCD W21-1a: Workers Signs
The W21-1a sign is covered in Section 6H.18 of the Manual on Uniform Traffic Control Devices, 11th Edition. Below are the provisions from that section that describe when the sign is used and how it is placed.
What it means and when it is used
- Option · Permitted (may)A Workers (W21-1) sign (see Figure 6H-1) may be used to alert road users of workers in or near the roadway.
- Guidance · Recommended (should)In the absence of other warning devices, a Workers sign should be used when workers are in the roadway.Page 806 MUTCD 11th Edition December 2023 Sect. 6H.18 to 6H.24
Where to read the rest
- Full text: MUTCD Section 6H.18: Workers Signs
- Mounting height, lateral offset and retroreflectivity for any sign: MUTCD sign placement guide
Related signs in Section 6H.18
Source: Manual on Uniform Traffic Control Devices, 11th Edition (Federal Highway Administration, December 2023, public domain). Excerpts are shortened and shown out of context; read the full section before specifying a sign. Your state may still be operating under the 2009 edition or a state supplement. Official manual: mutcd.fhwa.dot.gov.