SEATTLE — Federal investigators used 3-D laser scans Sunday to study what remained of a collapsed Washington state bridge as Gov. Jay Inslee announced temporary spans will be installed across the Skagit River within weeks — if plans go well.
The collapse, caused by a semitrailer carrying an oversize load striking the bridge, fractured one of the major trade and travel corridors on the West Coast. The interstate connects Washington state with Canada, which is about an hour north of Mount Vernon, where the bridge buckled.
After the collapse, semitrailers, travel buses and cars clogged local bridges as traffic was diverted through the small cities around the bridge. But overall, traffic was flowing as well as expected during the holiday weekend.
"We're going to get this project done as fast as humanly possible," Inslee, a Democrat, said Sunday. "There are no more important issue right now to the economy of the state of Washington than getting this bridge up and running."
Inslee said he hopes the temporary spans, each with two lanes for northbound and southbound traffic, will be finished in about three weeks' time or about mid-June. The spans will be pre-built and trucked to Mount Vernon.
The state plan also calls for a permanent span to be built and competed by autumn, officials said.
The federal government is expected to cover 100 percent of the costs of the temporary bridge and 90 percent of the replacement, said state Transportation Secretary Lynn Peterson.
The temporary span would be able to carry regular-sized cargos as well as cars. The speed limit would be lower than the 60 miles per hour allowed previously.
Barges arrived this weekend at the river with equipment ready to remove the mangled steel, pavement and cars in the water.
National Transportation Safety Board Chairwoman Debbie Hersman said on Sunday that the bridge had withstood other over-height collisions with vehicles in the past, with the most recent reported collision happening last October. She said evidence of other collisions can be seen in the spans still standing over the water.
Hersman also said a second truck with a similar cargo was traveling behind the truck involved in the collision. She said investigators are inspecting that cargo and truck to take measurements. The truck involved in the collision has been moved off the highway on-ramp where it has been parked since Thursday.
She said investigators have traveled to Alberta, Canada to inspect the trucking company's records.
Hersman added that if the truck had been in the left lane it likely would have cleared the bridge without a collision, but more precise measurements need to be taken. The bridge's height clearance varies across it.
"We know the company was required to establish that they could clear the entire route," Hersman said.