Jefferson County, MO Sign Regulations: Freeway-Facing Signs (2026)

4310(A)(3) of the Unified Development Ordinance, adopted April 2, 2008 and amended by Ordinance No. S. Highways 61 and 67, and State Highways 30, 141 and 231, all within unincorporated Jefferson County. A parcel that does not physically touch one of those rights-of-way cannot host a billboard regardless of its zoning district. The corridor limit works alongside the section's other standards: billboards are capped at 672 square feet per side, 20 feet in height and 50 feet in length excluding the base and supports, with no more than two faces and no stacking one billboard above another; they must sit at least 500 feet from a residence, 250 feet from a vacant residential zone district, or 50 feet from any non-residential structure; and no new billboard may be built within 1,400 feet of an existing billboard on the same side of the street.

Billboards are only allowed in the county's 'PC', 'PB', 'NPI', 'PI' and 'PM' zone districts to begin with, so the highway-frontage test in (A)(3) applies on top of that underlying district limitation. 4310(A)(8), since the UDO treats a billboard as a structure subject to the district's setback and intensity rules.