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

280 sets detailed siting standards for "standard outdoor advertising structures": off-site billboards with a face up to 300 square feet, sited to be read from an interstate or primary highway. Height is capped at 30 feet measured from the natural grade of the highway the sign is meant to be read from, or 50 feet above the grade where the structure itself is installed, whichever standard governs the site. Subsection (F)'s separation requirements keep billboards away from sensitive land uses: none may sit within 90 feet of the property line of the lot it stands on, within 400 feet of residentially zoned property, within 50 feet of an existing building or another on-premises advertising sign, within 500 feet of a rental property, park, hospital, playground, school, library, church or landmark, within 1,500 feet of a major highway interchange, within 500 feet of another standard outdoor advertising structure on the same side of the highway, or anywhere within a shopping center.

Subsection (H) further requires the structure to be located within 100 feet of a State right-of-way that is part of the national highway system, tying the entire regulatory scheme to genuine freeway-facing visibility rather than general commercial signage. Every billboard meeting these siting rules still needs a Special Use Permit with Planning and Zoning Commission review of its site plan before a permit issues.