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SR 18 - Issaquah Hobart Road to I-90 - Design Concepts

SR 18/I-90 Interchange

image showing SR 18/I-90 interchange design concept

The design concept for the SR 18/I-90 Interchange includes direct freeway-to-freeway ramps and roundabouts at I-90 on- and off-ramp intersections.  The design provides enough capacity to keep traffic moving freely until at least 2035.

Tiger Mountain Summit Interchange

image showing Tiger Mountain Summit interchange design concept

This design is a traditional "diamond interchange" that includes a bridge over SR 18 and access to Tiger Mountain Summit parking area.