Motorists who frequently travel on State Route 18 will need to find alternate routes during the weekend of Aug. 15-18, as the Washington State Department of Transportation (WSDOT) has announced several closures for maintenance and improvements. The major shutdown will be along the Tiger Mountain summit portion of SR 18, where both eastbound and westbound lanes will be completely closed for a span of multiple days.
As detailed in a news release by WSDOT, the closure will stretch from I-90 to Issaquah-Hobart Road beginning at 9 p.m. Friday, Aug. 15, and will last until 5 a.m. Monday, Aug. 18. The intent is to perform extensive work on the highway, including laying down a final layer of asphalt, guardrail installation, and various landscaping activities. Local traffic will still have access up to Southeast 104th Street, but passage over the summit itself will be restricted. Heavy vehicles and freight traffic are advised to reroute via I-405 and I-90 during the closures.
During this same period, WSDOT maintenance crews will be capitalizing on the traffic hiatus to conduct their annual highway upkeep. This work will include repairing damaged guardrails, repaving sections of road, and managing vegetation to improve signage visibility, according to the WSDOT statement. These coordinated efforts serve to condense the necessary closures into a single time frame, potentially easing future disruptions for travelers.
In addition to the closures over Tiger Mountain, WSDOT is also implementing westbound closures in Auburn. The right lane of westbound SR 18 between M and C Streets Southeast will see restrictions starting from 11 p.m. Friday, Aug. 15, to 1 a.m. Sunday, Aug. 17. A portion of the highway will then fully close at Auburn Way South from 2 a.m. Sunday, Aug. 17, to 5 a.m. Monday, Aug. 18. In this case, drivers will be detoured through nearby city streets and can expect to see police officers directing traffic at key intersections.
Although eastbound SR 18 through Auburn will not be affected, WSDOT warns that travelers should anticipate delays and consider planning their journeys outside of peak travel periods. The maintenance and improvement projects on SR 18 are part of a comprehensive plan that includes the recently opened I-90/SR 18 diverging diamond interchange, aiming to enhance traffic flow and safety in this area. Completion of the lane widening work along SR 18 is slated for the coming fall.
