The Alaskan Way Viaduct in Seattle will close this weekend in both directions, for its twice-yearly inspection and some roadwork at the entrance to the future state Route 99 tunnel.
Northbound traffic will close from 11 p.m. Friday until 5 a.m. Monday. Drivers will be detoured toward surface roads at South Spokane Street.
Southbound lanes will close from 5 a.m. to 6 p.m. on Saturday and Sunday, but will be open evenings. Drivers will be detoured at Denny Way, before the Battery Street Tunnel.
Inspections occur every October and March, in the wake of a 2001 earthquake that caused at least six inches of sinking and widespread cracking to the viaduct.
The northbound closure is longer because Seattle Tunnel Partners equipment will occupy the curved northbound highway lanes, near the stadiums.
Workers will extend a utility duct. They’ll also uncover part of a tunnel entrance ramp that was built, then temporarily filled, to create more surface area for earlier construction tasks in the area.
The tunnel, designed to bypass downtown, is to open in early 2019, followed by demolition of the 1953-vintage viaduct.