you have old Engineer Grade or High Intensity reflective material on your signs
that doesn’t meet the minimum MUTCD reflectivity requirements, see below table.
Also available here: https://mutcd.fhwa.dot.gov/htm/2009/part2/part2a.htm#table2A03
size R1-1 STOP sign should I use?
For public roads 30” x 30” is the minimum size R1-1 STOP sign you can use. In some instances a 36” x 36” R1-1 or even a 48” x 48” R1-1 STOP sign is required.
How high off the road surface does my sign
have to be mounted?
For signs in a rural area signs must be mounted 5FT off the road surface. For signs in a business, commercial, or residential area signs must be mounted 7FT off the road surface. See Figure 2A-2 below for more information.
How deep in the ground should I bury my sign posts in the ground?
This varies from state to state depending on the frost line. We recommend burying posts at least 3FT into the ground. You can reach out to your local road agency for more information.
How far off the road should my sign post be
See Figure 2A-2 below for more information:
grade of reflective material do I want for my STOP sign?
TYPE IV HIGH INTENSITY PRISMATIC is the minimum reflective material you should use on your STOP sign. In some cases TYPE IX DIAMOND GRADE is needed.
check with your local road agencies for more information.