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Workers Sign (W21-1): What the Worker Symbol Means

Workers warning sign, W21-1: black silhouette of a worker with a shovel on an orange diamond
Workers symbol sign (W21-1). Illustration drawn by Safe Pass Traffic; not to scale.

The orange diamond showing a person with a shovel is the Workers sign, W21-1. It warns that people are working in or near the roadway ahead. Slow down, stay alert and give them room.

What it means

Section 6H.18 of the California MUTCD 2026 Edition says a Workers (W21-1) sign may be used to alert road users of workers in or near the roadway. In the absence of other warning devices, a Workers sign should be used when workers are in the roadway. The WORKERS (W21-1a) word sign may be used as an alternate to the symbol version.

The symbol is meant to be read at a glance: a worker with a shovel next to a pile of material. It carries the same message as the word sign.

What drivers often get wrong

  • Deciding nobody is there. Workers can be behind equipment, in a trench or just around a bend. Treat the sign as real until you are past the work area.
  • Mixing it up with the flagger sign. The Workers sign does not mean someone will stop you. The Flagger sign (W20-7) shows a person holding a paddle and warns of a flagger ahead.
  • Assuming fines always double. Under California Vehicle Code Section 42009, doubled fines apply only when work is actually being performed by workers and work-zone traffic control devices or warning signs are posted. The sign itself does not double anything; the law’s conditions do.

Where it goes in a work zone

Like other warning signs, the Workers sign goes in the advance warning area ahead of the activity. Spacing varies with road type, condition and speed (Section 6H.02). When a series of advance warning signs is used, the one closest to the work ranges from about 100 feet on low-speed urban streets to 1,000 feet or more on freeways and expressways. Where several signs are needed, ROAD WORK AHEAD (W20-1) should be the first one road users see.

On short, low-impact jobs where few other devices are used, the Workers sign may be the main warning, which is why the manual says it should be used when workers are in the roadway and no other warning devices are present.

What contractors need to know

  • Decide early whether the W21-1 symbol or W21-1a word version will be used; the permitting agency may prefer one.
  • A Workers sign left up when nobody is working teaches drivers to ignore it; the plan and the agency’s rules should say when it is displayed.
  • The Workers sign warns; it does not replace channelizing devices, flaggers or a lane closure when the work actually blocks traffic.
  • Sign placement, spacing and the rest of the layout belong on the traffic control plan, and the agency may add its own requirements.

Related signs

Frequently asked questions

What is the difference between W21-1 and W21-1a?

W21-1 is the symbol version showing a worker. W21-1a spells out WORKERS. The manual allows the word sign as an alternate to the symbol.

Is the Workers sign required?

The manual says it may be used whenever workers are in or near the roadway, and it should be used when workers are in the roadway and no other warning devices are present. Agencies may set further requirements.

Sources

Need this sign on a traffic control plan?

Safe Pass Traffic prepares PE & TE stamped traffic control plans, striping plans and typical plans for projects statewide in California, and helps with the permit submittal. We draw the plan that shows which signs go where; your contractor or traffic control provider sets them in the field. Call or text (714) 362-1348 or request a quote.