Full closure of SR 18 planned near Snoqualmie for I-90/SR 18 interchange project, July 9-13

UPDATE: July 7, 2026 - The full closure of SR 18 for final paving of the I-90/SR 18 diverging diamond interchange has been rescheduled to July 9-13.

Work is the last extended weekend closure of project; I-90 remains open throughout the weekend

SNOQUALMIE - After nearly four years of construction, the Interstate 90/State Route 18 interchange project is nearly complete - with one final extended weekend paving closure that begins Thursday, July 9.

From 9 p.m. Thursday, July 9, to 5 a.m. Monday, July 13, traffic will not be allowed either direction of SR 18 beneath the I-90 bridges near Snoqualmie. All right-turning on- and off-ramps will remain open at the I-90/SR 18 interchange during this full closure.

People traveling through the I-90/SR 18 interchange should plan ahead, add extra time for travel, especially during peak travel times, and follow signed detours.

What to expect July 9-13

Eastbound and westbound I-90 traffic will not be affected during most of the closure, but people traveling through the area should be aware that:

• Vehicles will not be permitted on either direction of SR 18 beneath the I-90 bridges.
• Traffic on the eastbound and westbound I-90 off-ramps will only be able to turn right.
• All eastbound SR 18 traffic must use the eastbound I-90 on-ramp. Travelers needing to go westbound on I-90 or to Snoqualmie Parkway should follow the detour to Exit 27, North Bend/Snoqualmie and loop back to westbound I-90.
• Southbound traffic on Snoqualmie Parkway must use the westbound I-90 on-ramp. Travelers needing to go eastbound on I-90 or to westbound SR 18 should follow the detour to Exit 20, Southeast High Point Way and loop back to eastbound I-90.

During this closure, construction crews working for the Washington State Department of Transportation will complete final paving for the Diverging Diamond Interchange under I-90. Crews will also remove temporary barrier, install permanent impact attenuators, install guardrail, paint temporary striping, install electrical loops, place curbing and adjust stormwater drainage. This closure requires dry weather and may be rescheduled with short notice if rain is forecast.

Detour routes

People can detour around the closure using eastbound and westbound I-90 and loop around at nearby interchanges - Southeast High Point Way (exit 20) to the west and Southeast North Bend Way/Winery Road (exit 27) to the east.

• Westbound I-90 to westbound SR 18: Continue westbound on I-90 to exit 20, Southeast High Point Way, loop back to eastbound I-90 and exit at SR 18/Snoqualmie Parkway.
• Westbound SR 18/Snoqualmie Parkway to eastbound I-90: Use the westbound I-90 on-ramp to exit 20, Southeast High Point Way, and loop back to eastbound I-90.
• Eastbound SR 18 to westbound I-90: Use the eastbound I-90 on-ramp to exit 27, North Bend/Snoqualmie (Winery Road), and loop back to westbound I-90.
• Eastbound I-90 to Snoqualmie Parkway: Continue eastbound on I-90 to exit 27, North Bend/Snoqualmie (Winery Road), loop back to westbound I-90 and exit at SR 18/Snoqualmie Parkway.
• Eastbound SR 18 to northbound Snoqualmie Parkway: Use the eastbound I-90 on-ramp to exit 27, North Bend/Snoqualmie (Winery Road) loop back to westbound I-90, then exit at SR 18/Snoqualmie Parkway.
• Southbound Snoqualmie Parkway to westbound SR 18: Use the westbound I-90 on-ramp to exit 20, Southeast High Point Way, loop back to eastbound I-90, then exit at SR 18/Snoqualmie Parkway.

To help keep traffic moving, the Preston/Fall City exit on westbound I-90 should be used primarily by local traffic. Travelers can potentially save time by using the signed detour at Southeast High Point Way or by using alternate routes.

Freight traffic should not use Issaquah city streets or Issaquah-Hobart Road, which are not suitable for semi-trucks. Similarly, eastbound SR 18 freight traffic cannot use Issaquah city streets to access I-90.

Once all final paving is completed, there will be a series of smaller closures of SR 18 scheduled to install permanent lane markings throughout the project area.

Additional closures this weekend

Revive I-5 preservation work will close all lanes of northbound Interstate 5 across the Ship Canal Bridge from I-90 to Northeast 45th Street the weekend of July 10-13.

All northbound traffic will use the I-5 Express Lanes. During this closure, crews will reinstall construction barriers and set up a new work zone in the right two lanes of northbound I-5 on the Ship Canal Bridge. The I-5 Express Lanes will return to a northbound-only configuration through the end of the year while this work is underway.

People travelling in the Seattle and Snoqualmie areas should plan for long delays and heavy traffic conditions.