Drivers traveling Interstate 90 on Snoqualmie Pass may encounter late-night backups due to construction this summer.
The Washington State Department of Transportation advises travelers to hold tight until October, as the work is expected to improve capacity, safety and flow along the busy highway.
The work zone, which stretches west from the Snoqualmie Pass snow shed for about three miles, adds a third lane in both directions. Lanes will be aligned to fix sharp curves, and chain-up and chain-off areas will be extended. Six new bridges will be constructed.
Back-ups are due to one-hour road closures, occurring at dusk on Monday and Thursday evenings, allowing workers to blast, dig and stabilize rock walls.
The freeway is closed at 8 p.m. for approximately 45 minutes to conduct the blasting and clean debris off the road.
“The blast is part of the slope stabilization work,” said Bob Hooker, WSDOT spokesperson. “We’re drilling into existing rock cut, cropping and fracturing that material so it can be excavated. It’s not a glorified blast like on TV, but it’s enough explosives to excavate the rock out.”
Two detours have been built at each end of the project. The west detour allows workers to start construction of three of the six bridges aroudn the Gold Creek area.
The east end allows rock excavation where the blasting begins.
Eastbound lane work will be completed next summer. Westbound traffic lanes will be complete by 2012.
Project manager Kelly Griffin described 2010 as the “head start year,” as WSDOT has started on the two major sites, Gold Creek Bridges and the rock cut.
“We’ve conducted blasts, and everything has gone according to plan,” Griffin said. “I would say there’s no major obstacles, but when you add lanes to freeways there’s always problems—(that’s) nothing out of the ordinary.”
Griffin said the impacts to traffic have been reasonable, given what they are doing.
Since construction began in June, the city of North Bend has not experienced traffic impacts from the project.
The city is aware of the long term safety problems at the top of Snoqualmie Pass and supports the redevelopment and expansion of the lanes.
“It’s much needed, based on safety considerations,” said North Bend City Administrator Duncan Wilson.
Construction was delayed due to poor weather this spring.
“We’re a little behind, but we can make up the time,” Griffin said.