What work is happening while tunneling is on hold?

Tags: sr99

Construction is taking place at the north and south end of the SR 99 tunnel. The north portal is taking shape near the Space Needle, including construction of the pit where the SR 99 tunneling machine will emerge at the end of tunneling. Crews are also building the cut-and-cover tunnel that will connect the bored section of the tunnel to SR 99/Aurora Avenue North.

Crews at the south portal are continuing to work on the south portal operations building, which will control safety features, lighting and ventilation within the future tunnel. Work is also focused on the south cut-and-cover tunnel that will connect the new south-end SR 99 roadway with the bored section of the tunnel.

Crews in Frederickson, Wash. continue to produce the concrete tunnel segments that are pieced together to form the exterior walls of the SR 99 tunnel.