The Alaskan Way Viaduct snakes its way along the waterfront. This view is looking south. The viaduct is set to close next Jan. 11, and then be demolished.
Travelers will get a few more months to brace for the permanent closure of the Alaskan Way Viaduct, which is being postponed until Jan. 11.
On that date, Highway 99 traffic will be blocked for three weeks between Spokane Street and Belltown, causing delays and congestion until interchange ramps are connected and a new four-lane tunnel opens to traffic.
The January timeline, announced Monday, stretches the $2.2 billion megaproject a full three years beyond the original schedule under then-Gov. Chris Gregoire.
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It also abandons recent forecasts by the Washington State Department of Transportation (WSDOT), to accomplish the changeover from elevated to underground lanes this fall.
The deep, concrete tunnel through downtown Seattle is built, and tests of signals and safety systems are going well overall, said project administrator Brian Nielsen. WSDOT published summer video to herald the near-ready tunnel.
However, he said Monday that state and city agencies chose not to push for a late-October date to retire the viaduct. If rainstorms hit, paving for the tunnel entrances might slide into late November. “Our various contractors just aren’t quite there,” Nielsen said.
Officials also worried about disrupting holiday shopping and celebrations.
Seattle has a longtime moratorium to limit other late-year roadwork, said Heather Marx, downtown mobility director for the Seattle Department of Transportation.
“Between Thanksgiving and New Year’s, we limit the amount of construction that can take place in the right-of-way, to support the retail community during the holiday season,” she said. “It’s a really heavy travel time, trying to make it to grandma’s house,” for instance.
SDOT also believes people need the additional time to prepare their alternate travel plans, Marx said.
Although the delay may help winter commerce, it also pushes next year’s Viaduct demolition into the summer tourism season, instead of a May completion WSDOT hoped for. Nielsen said contracts will be renegotiated with Scarsella Bros., for ramp-connection work and with Kiewit Infrastructure West, for demolition and the waterfront boulevard.
Asked if new delays would cause at least $10 million in cost overruns, Nielsen said the expense should be less.
Nielsen gave three other traffic updates:
—Two lanes will be provided in each direction on surface Alaskan Way, where a thinner detour road will be moved westward, from under the Viaduct. The route was recently paved near Colman Dock.
—The Viaduct’s southbound Atlantic Street exit in Sodo will close one week before the Jan. 11 highway closure, to give workers a head start completing the tunnel connection there.
—After the tunnel opens, crews need another week to finish linking the earthquake-resistant northbound overpass to the new Dearborn Street/Sodo interchange — better than the two weeks WSDOT earlier forecast. Until then, drivers coming from West Seattle and Burien must go all the way through the tunnel, which lacks mid-downtown exits, until reaching the new South Lake Union interchange.
Nielsen emphasized that when tunnel-boring machine Bertha broke into daylight on April 4, 2017, the official schedule showed the beginning of 2019 to open the new tunnel. As deck work within the tunnel moved quickly, state managers and tunnel-builder Seattle Tunnel Partners aimed toward a sooner fall 2018 opening, until a decision by local agencies last week to wait for January.
Tunnel contractors previously took two years to repair and adjust Bertha after a breakdown in late 2013 — itself an epic project that featured a 4-million pound lift of the disc-shaped cutterhead to the surface.
Total costs are $2.2 billion for the tunnel, and $3.3 billion overall including ramps, demolition and connecting roads. Of that, about one-fourth is federally funded, with the remainder from state gas tax, the Port of Seattle and tolls. Figures don’t include whatever the state might pay in litigation, where contractors seek payment for up to $600 million in overruns.
Toll rates are expected to range from $1 off-peak to $2.25 in late afternoon, but the state will wait a few months past the opening to begin collecting them.
