What Size Should a Street Name Sign Be?

Introduction

With their varying heights and widths, Street Name Signs can take on many different appearances. Each dimension of a sign blade is chosen for specific purposes, most important of all being readability. The correct sign size takes roadway speed, visibility, and street name length into account, as well as local traffic agency requirements.

Speed Affects Minimum Letter Height

When local jurisdictions set requirements for street name letter height, that influences the sign size that’s needed. Those requirements are generally based on federal MUTCD guidance, including the recommendations in Table 2D-6 (2D.45).

The speed limit that counts is the one on the road the sign faces, not the street named on the sign (2D.45).

The overarching principle is that the larger the letters used, the more easily seen the Street Name Sign is. Visibility most often translates into safer outcomes for drivers on the road.

General MUTCD Guidance

The MUTCD gives guidance on every part of a Street Name Sign’s design. Overall, lower-speed residential roads don’t call for as much visibility as faster roads, so smaller lettering is often acceptable. Higher-speed, major city roads typically need larger lettering to provide essential visibility from a distance.

Common MUTCD Street Name Blade Heights

When regulations set a specific Street Name Sign letter height, the blade height adjusts to best fit the letters. Below are common blade heights, with the upper-case and lower-case letter heights that fit them.

8- to 9-inch Street Name Signs

The MUTCD sets the minimum blade height, which is 8 inches tall (Table 2D-1). Blades shorter than the 12-inch standard may only be used on low-speed roads, alleys, site roadways open to public travel, and low-volume rural roads at 30 mph or less (2A.07). On two-lane local streets at 25 mph or less, these blades can use 4-inch upper-case letters with 3-inch lower-case letters:

• Residential neighborhoods and HOAs
• Apartment communities
• Shopping center driveways

When required or most helpful, these Street Name Signs also use 6-inch upper-case letters with 4.5-inch lower-case letters.

9-inch Street Name Signs

A 9-inch blade fits 6-inch upper-case letters and 4.5-inch lower-case letters, the recommended letter heights for two-lane roads and for multi-lane roads at 40 mph or less (Table 2D-6). Because it is shorter than the 12-inch standard, a 9-inch blade fits the same low-speed settings as the 8-inch size, such as:

• Narrow, lower-speed roads
• Neighborhood collector streets
• Locations that need larger lettering than 4-inch letters

12-inch Street Name Signs

The 12-inch Street Name Sign is the standard sign height on conventional roadways (Table 2D-1). Those roadways include:

• Higher-speed city streets
• Multi-lane arterials
• Locations that need maximum visibility

Multi-lane roads with speed limits over 40 mph typically use 8-inch upper-case letters with 6-inch lower-case letters, and others use 6-inch letters.

18- and 24-inch Street Name Signs

18-inch Street Name Signs have an oversized blade height. They’re usually seen on wide, higher-speed roads. 24-inch Street Name Signs are mounted overhead on signal mast arms or span wires, using overhead sign brackets. As the largest sign size, they have 12-inch upper-case letters and 9-inch lower-case letters (Tables 2D-1 and 2D-6).

A Note on 6-inch Street Name Signs

The MUTCD doesn’t apply to private roads that are closed to the public at all times (1B.01). There, you can use shorter 6-inch Street Name Signs if your local jurisdiction allows it.

What Can Affect Sign Blade Width

Street Name Length

The MUTCD recommends minimum letter heights and acknowledges that post-mounted Street Name Signs vary greatly in width (Tables 2D-1, 2D-6). The following street names require varying sign widths, with estimates pulled from our sign builder:

• Oak St – 18 inches wide
• Olive Branch Rd – 36 inches wide
• Mountain View Pkwy – 48 inches wide
• Veterans Memorial Blvd – oversized width

In general, the longer the street name, the wider the Street Name Sign. Many street name descriptors, such as “Avenue” or “Boulevard,” can be abbreviated, but the street name itself should not be (2D.45). See Why Do Modern Street Name Signs Use Mixed-Case Letters? for more on lettering.

Community Logos

A community logo can be added to the left of the Street Name Sign. The logo extends the sign blade width, and it can’t be any taller or wider than the upper-case letter. Only cities or government-approved entities can design Street Name Signs with their logo on roads open to public travel (2D.45).

Block or House Numbers

Section 2D.45 outlines how block or house numbers can be added to Street Name Signs. As a supplemental legend, those numbers can aid navigation for emergency responders and road users. You’ll see block or house numbers on the left, right, or both sides, which will make Street Name Signs longer. They should be at least two-thirds the height of the street name, and no less than 3 inches.

Directional Arrows

When one road has two different street names for each direction of travel, both names can appear on one sign. Optionally, directional arrows can be added to point left and right toward each side of the road. Arrows aren’t used where one would point against traffic on a one-way street, or toward a turn that isn’t allowed (2D.45).

Conclusion

To best follow local regulations on Street Name Sign sizes, consider street sign letter height requirements and the length of the street name itself. That way, you can both ensure compliance and provide the appropriate readability for drivers on the road. Design yours in our custom street sign builder, see Custom Street Name Signs for HOAs, Neighborhoods, and Private Roads, and choose street name sign brackets to mount them.