After years of planning and nearly 20 months of construction, the state’s second diverging diamond interchange is almost ready to open at the I-90/SR 18 interchange near Snoqualmie.
To complete the final phase of work, both directions of SR 18 beneath the I-90 overpasses will close from 9 p.m. Thursday, July 17, through 5 a.m. Friday, July 25. Drivers should plan for delays and follow signed detours during this full closure.
This extended closure allows crews to finish critical construction tasks, including drainage and electrical work, curbing, traffic signal setup, and new ramp connections. It also enables a traffic shift into the new diverging diamond pattern, which will improve traffic flow and safety by reducing conflict points in the interchange from 26 to 14. Some of the work planned during the closure depends on dry weather and may be rescheduled if it rains…