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  1. Home
  2. Warning Signs
  3. Workers Ahead Sign - W21-1

Workers Ahead Sign - W21-1

Workers Ahead Sign - W21-1
Min: 1 • Max: 1000
Unit Price:$0.00
Quantity:× 1
Total:$0.00

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Choose Your Reflectivity Grade

Compare visibility, durability, and ideal applications

Type I

Engineering Grade

Ideal Use

Parking lots

Brightness

Standard

General Lifespan

7 years

Night-time Visibility

500 feet away

Type IV

High Intensity Prismatic

Ideal Use

Roadways

Brightness

High

General Lifespan

10 years

Night-time Visibility

1000 feet away

Type IX

Diamond Grade

Ideal Use

High-speed roadways

Brightness

Maximum

General Lifespan

10+ years

Night-time Visibility

1500 feet away

Product Details

Workers Ahead Sign - W21-1

This heavy-duty warning sign is designed to enhance roadway safety by alerting drivers to the presence of workers in construction or maintenance zones. Constructed with high-quality aluminum featuring radius corners and 3/8 inch prepunched holes, the sign ensures durability and easy installation. Manufactured with high-intensity and diamond grade reflective sheeting, the Workers Ahead sign meets both state and federal Department of Transportation (DOT) and Manual on Uniform Traffic Control Devices (MUTCD) guidelines. Compliant with MUTCD Figure 6F-4, this W21-1 symbol sign provides critical visual communication to help protect workers and reduce potential roadside accidents.

Spec • 2026
MUTCD Compliant

Sign Specifications

MUTCD Code

W21-1

Sign Type

Construction Sign

Shape

Diamond

Standard warning sign shape

Colors

ABC

Orange background

Black legend

Compliance

MUTCD Compliant: This work zone warning sign meets federal standards per MUTCD Section 6F.16. Orange background indicates temporary traffic control.

SizeDimensionsApplication
Minimum30x30"Low-volume roads
StandardDefault36x36"Conventional roads
Expressway48x48"Expressways and freeways
Compliance & Certifications

MUTCD Compliant

Federal standards

DOT Approved

State & Federal

ASTM D4956

Type III/IV/XI

10+ Years

Durability

Engineer Grade (EG)

Type: ASTM Type I

Lifespan: 5-7 years

Brightness: ~50 cd/lux/m²

Parking lots, low-speed areas, non-critical signage

Recommended

High Intensity Prismatic (HIP)

Type: ASTM Type III/IV

Lifespan: 10 years

Brightness: ~360 cd/lux/m²

Traffic signs, work zones, roadways

Diamond Grade (DG3)

Type: ASTM Type XI

Lifespan: 10-12 years

Brightness: ~580 cd/lux/m²

Critical signs, freeways, overhead signs

Install in advance of work zone per MUTCD Chapter 6F. Orange background for temporary conditions. Remove or cover when work not in progress.

MUTCD Reference: Section 6F.16

Reference: MUTCD Section 6F.16

Often Paired With

Signs commonly installed together per MUTCD guidelines

Road Work (distance) Sign - W20-1

W20-1

Road Work (distance) Sign

View All Warning Signs