MUTCD Stop Signs FAQ

Frequently Asked Questions about MUTCD Stop Signs

1) What size stop sign do I need?

• 12 x 12" - This is a novelty size and makes for great gifts or decor
• 18 x 18" - These are great for bicycle traffic control and shared-use pathways
• 24 x 24" - This size works ideally for private roadways and parking lots
• 30 x 30" - This is the minimum size required for official street stop sign applications
• 36 x 36" - This is the minimum size required for stops with multi-lane approaches and hazardous intersections

2) How high must my stop sign be mounted?

*Most Common Application

In business, commercial, or residential areas (Fig. A)

the short answer is stop signs need to be mounted 7 feet above the curb, sidewalk, or edge that it's mounted on. The full MUTCD specification is listed as: the minimum height, measured vertically from the bottom of the sign to the top of the curb, or in the absence of curb, measured vertically from the bottom of the sign to the elevation of the near edge of the traveled way, of signs installed at the side of the road where the view of the sign might be obstructed, shall be 7 feet.
For signs installed above sidewalks: The minimum height, measured vertically from the bottom of the sign to the sidewalk, shall be 7 feet.

In rural areas (Fig. B)

The minimum height is 5 feet and measured vertically from the bottom of the sign to the elevation of the near edge of the pavement.

Overhead signs (Fig. C)

There must be a vertical clearance of no less than 17 feet to the sign, sign bridge, or light fixture over the entire width of the pavement and shoulders except where the structure on which the overhead signs are to be mounted or other structures along the roadway near the sign have a lesser vertical clearance.

Source: Federal Highway Administration Manual on Uniform Traffic Control Devices (MUTCD)

3) What's the difference between the different levels of stop sign reflectivity?