Attention Seattle drivers---"SR 99 construction bypass: Keeping traffic moving through SODO" (video)

wsdot, with video (03:44):

On Oct. 21, we will close SR 99 and begin demolishing part of the viaduct. When SR 99 reopens to traffic on Oct. 31, both north and southbound traffic will be traveling on the first of two new bridges currently being built to the west of the existing viaduct. Drivers will pass through a large bypass located between South King Street and South Royal Brougham Way. The bypass will connect the new SR 99 bridge to the existing viaduct at South King Street. It also keeps traffic on SR 99 moving while giving central waterfront viaduct replacement crews enough space to work.

South of South King Street, SR 99 will have two lanes in each direction. North of South King Street the viaduct will remain in its current configuration with three lanes in each direction.

Howie P.S.: Is this a "temporary" viaduct?