R1-1 STOP Standard Sizes

This page shows the common MUTCD standard sizes for the R1-1 STOP sign. Use this information to select the appropriate size based on roadway speed, traffic conditions, and visibility needs. All dimensions are in inches.

Common Sizes

Standard nominal sizes per MUTCD.

Roadway Applications

Size selection based on speed, ADT, and roadway environment.

Visibility / Reflectivity

High-intensity reflective sheeting required at night.

Mounting Guidance

Proper mounting height and placement for optimal visibility.

R1-1 STOP Sign Standard Size Chart

18 in18" × 18"
Typical Use
Very low-speed areas, private roads, and parking lots
Notes
Minimum size permitted. Short sight distance.
24 in24" × 24"
Typical Use
Low-speed local streets, residential neighborhoods
Notes
Most common size for local applications.
30 in30" × 30"
Typical Use
Collector streets, higher speeds or higher traffic volumes
Notes
Improved visibility for higher volumes.
36 in36" × 36"
Typical Use
Major collectors, arterial streets, multilane approaches
Notes
Recommended for higher speeds (≥ 40 mph).
48 in48" × 48"
Typical Use
High-speed roadways, multilane highways, special visibility needs
Notes
Maximum standard size for enhanced visibility.

Nominal Size	Dimensions	Typical Use	Notes
18 in	18" × 18"	Very low-speed areas, private roads, and parking lots	Minimum size permitted. Short sight distance.
24 in	24" × 24"	Low-speed local streets, residential neighborhoods	Most common size for local applications.
30 in	30" × 30"	Collector streets, higher speeds or higher traffic volumes	Improved visibility for higher volumes.
36 in	36" × 36"	Major collectors, arterial streets, multilane approaches	Recommended for higher speeds (≥ 40 mph).
48 in	48" × 48"	High-speed roadways, multilane highways, special visibility needs	Maximum standard size for enhanced visibility.

R1-1 STOP Sign Dimensions

W (Width)

H (Height)

For a octagon, Width (W) and Height (H) follow the nominal size at each dimension.

When Each Size Is Typically Used

18 in Octagon
Very low-speed areas, private roads, and parking lots
24 in Octagon
Low-speed local streets, residential neighborhoods
30 in Octagon
Collector streets, higher speeds or higher traffic volumes
36 in Octagon
Major collectors, arterial streets, multilane approaches
48 in Octagon
High-speed roadways, multilane highways, special visibility needs

Material / Visibility Notes

✓
High-Intensity Reflectivity
Signs should use high-intensity or diamond-grade retroreflective sheeting for nighttime visibility.
✓
Sign Legibility
Larger signs improve legibility and driver response time.
✓
Nighttime Visibility
Proper size and reflectivity enhance visibility in low-light conditions.
✓
Maintenance
Keep signs clean and unobstructed to maintain retroreflective performance.

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. Local jurisdictions may impose additional requirements, and final selection, placement, and dimensions may require engineering judgment or agency approval. Written against California MUTCD 2026 (effective January 18, 2026) and the Federal MUTCD 11th Edition. Official sources last verified June 2026.

Need to Rent or Purchase This Sign? Contact Public Ready.

Public Ready supports sign selection, project-ready sign packages, and equipment sourcing through qualified providers — with expert support built for compliance.

Contact Public Ready or call (323) 900-9824