Issaquah, WA Sign Regulations: Freeway-Facing Signs (2026)

The freeway rule applies to permanent primary and secondary signs on a building or business adjacent to I-90. Three situations fall outside it: a street sits between I-90 and the property (the code names SE 62nd Street as the example), the Director decides the elevation parallel to the freeway, including on-ramps and off-ramps, is the building's primary frontage, or a development has two or more buildings, in which case only the building or buildings closest to the I-90 right-of-way are restricted.

For a restricted building, the elevation parallel to the freeway is the secondary frontage and carries no signage at all. The code defines a parallel elevation as one at an angle of 45 degrees or less relative to I-90. A perpendicular elevation, meaning an angle greater than 45 degrees but less than 110 degrees relative to I-90, can carry a wall sign with letters no taller than two feet and a length of 15 feet, and the total sign area cannot exceed 30 square feet. The Director decides which side is the primary frontage (the side with main vehicle or pedestrian access or the business's primary orientation) and which is secondary.

The prohibited-sign list in LUC 18.612.050(K) backs this up: a sign inconsistent with the I-90 restrictions in 18.612.080(D)(1)(a) is not allowed. Section 18.612.050(J) separately bars any sign erected or maintained in violation of the Highway Advertising Control Act or the Scenic Vistas Act, Chapter 47.42 RCW. The sign chapter's purpose clause, 18.612.010(A)(5), ties the whole scheme to the Mountains to Sound Greenway and to managing the type, location and proliferation of signage that is visible from I-90.

A permanent sign permit is valid for one year from issuance, and the sign must be fully installed by then or the applicant files a new application and fee. Permit fees follow the City's adopted fee schedule, and electric or illuminated signs need an additional permit from the State Electrical Inspector.