SEATTLE — Bertha has built about 30 percent of the section of the new State Route 99 tunnel that's forcing the closure of the Alaskan Way Viaduct, raising the possibility of an early end to the traffic closure if the pace continues.
On Monday morning, David Sowers of the Washington State Department of Transportation told reporters Bertha had traveled 78 of the 385 feet it needs to go before traffic can return to the viaduct.
"We're getting close to 20 percent complete. It's still too early to speculate at that rate whether or not we'll finish early or even on time," Sowers said.
The traffic closure began April 29 and was expected to last about two weeks.
The machine was just beneath the west edge of the viaduct near Yesler Way and has yet to travel beneath much of the structure.
Sowers said, as expected, contractors left a concrete-fortified maintenance stop slowly and have since picked up the pace, which can fluctuate.
"That doesn't necessarily guarantee that we're going to stay on that pace for the next 72 hours," Sowers said.
But early Monday, a tweet from Bertha's Twitter account said the tunneling machine had excavated about 106 feet.