King County, WA Sign Regulations: Freeway-Facing Signs (2026)
Key Facts
- Allowed zones
- CB, RB, I only
- Max distance from arterial
- 100 feet
- Type I setback from residential
- 330 feet
- Height cap
- 35–45 feet by zone
- Faces per direction/mile
- 5 maximum
Summary
In unincorporated King County, billboards facing traffic corridors may only sit on CB, RB, or I zoned land, must be within 100 feet of the adjacent arterial, and are capped at five faces per direction of travel within a mile.
A. All billboard alterations or relocations shall comply with the following location and design standards: 1. Billboards shall only be located on sites zoned CB, RB or I; 2. No more than five billboard faces shall be oriented toward and visible from the same direction of travel within one mile of the proposed relocation site as measured along the adjacent roadway...7. No billboard shall be located more than one hundred feet from any adjacent arterial.
Full Breakdown
King County Code 21A.20.130 controls billboards, the county's category for large freeway- and arterial-facing signs. They're allowed only in Community Business, Regional Business, and Industrial zones, must sit within 100 feet of the adjacent arterial, and are limited to five faces visible from the same direction of travel within a one-mile stretch. Type I billboards must stand at least 330 feet from rural and residential zones (Type II, 100 feet), and height is capped at 35 feet in CB/RB zones or 45 feet in I zones, or 15 feet above nearby building heights, whichever is less. This applies only to unincorporated county land. Seattle, Bellevue, Kent, Renton, Federal Way, and Auburn each set their own sign codes.
Violations & Fines
Altering, relocating, or erecting a billboard without a county alteration/relocation permit is barred; uninventoried billboards can't be modified until King County issues one, per K.C.C. 21A.20.160D and 21A.20.140C.
Frequently Asked Questions
Does this cover billboards inside Seattle?
Can a billboard be sited on any zoned lot near a freeway?
Sources & Official References
Other rules in King County
Compare King County to another location·View the Washington sign regulations overview
See something wrong?
Help us keep this page accurate. If you notice an error or outdated information, let us know.