The I-5 bridge across the Skagit River shortly after its collapse Credit: Martha T/Flickr
Gov. Jay Inslee announced on Sunday that a temporary replacement for the I-5 Skagit River bridge should be in place by mid-June. A permanent replacement is in line for September.
Transportation secretary Lynn Peterson explained how the state plans to construct the temporary bridge span in the river just west of the gap in the existing bridge. Once workers clear away debris from the collapsed bridge, the temporary four-lane span will be "rolled" into place and connected. Exactly how to roll that temporary section is still being studied. And the entire replacement strategy remains contingent on what inspections reveal about the condition of the piers on either side of the gap.
The temporary bridge section will be slightly narrower than the rest of the bridge, so the current 60 mph speed limit will be lowered after the temporary span is installed.
A permanent replacement section is expected to be built and installed sometime in September. The stretch of I-5 over the Skagit will likely be closed for two weeks during the installation. Peterson is confident that the September timetable is solid. The Atkinson Construction Co. of Broomfield, Colo. – with an office in Renton – will tackle the Skagit work. Atkinson has handled several highway and bridge projects in Washington.
Peterson said the original $15 million cost estimate to fix the bridge appears accurate. The state has already received $1 million from the federal government.
Sen. Maria Cantwell (D-Washington) expressed her certainty on Sunday that the feds will provide most of remaining money through a U.S. Department of Transportation emergency fund designed for quick repairs. "This is the type of incident that qualifies for the fund," Cantwell said.
That federal appropriation is contingent on the state providing 10 percent of the replacement money. Gov. Inslee said the state will raise its share either through legislative appropriations or from existing state funds, calling the Skagit River bridge replacement the state’s top near-term transportation priority.
Inslee, Cantwell and U.S. Rep. Suzan DelBene (D-Washington) stressed I-5’s role as a vital north-south artery through Washington and along the West Coast, and said the current gap handicaps the economies of Skagit County, Washington and the entire West Coast. Cantwell said $13.9 billion in commercial traffic crosses the bridge each year.
The Skagit River bridge handles roughly 71,000 high-speed vehicles a day;12 percent are commercial. With its closure, four smaller bridges on side roads are being forced to handle unprecedented volumes of traffic.
The 160-foot span collapsed at roughly 7 p.m. Thursday when a southbound semi, carrying an oversized load of drilling equipment, clipped an overhead beam and sent a section of bridge tumbling into the Skagit. The moment of impact and its immediate aftermath were captured by a private security video. About 50 vehicles managed to stop in time, but one car and a pickup truck hauling a trailer slid 50 feet into the river, half sinking in the Skagit's waters. The occupants crawled out onto the vehicle roofs where they were rescued by local officers. The three suffered only minor injuries and were taken to local hospitals.
The Alberta-based semi-truck had a state permit to carry its oversized load of 15 feet, nine inches. Washington requires bridges with a clearance of less than 15 feet, three inches to post clearance heights. That’s three inches more conservative than the national standard. But as an added safety cushion Washington lists a bridge's clearance as three inches less than the measured height.
On the I-5 Skagit River bridge, the published heights are 14 feet, five inches at the outermost curb; 17 feet, three inches at the line dividing the outer and inner lanes; and 17 feet, nine inches near the bridge's center. Again, the actual heights are three inches higher.
Washington's transportation department, state patrol and the National Transportation Safety Board are conducting parallel investigations of the accidents.
The collapse of the 58-year-old bridge has raised concerns about the safety of Washington's 7,840 bridges. "You see an errant truck has the capability to bring down a bridge," Peterson said.
The Research Information Program, citing Federal Highway Administration figures, reported that, as of 2012, 25 percent of the nation's bridges, 20 feet or longer, were either “functionally obsolete” or, worse still, "structurally deficient."
The federal figures showed that 26 percent of Washington's bridges fall into the structurally deficient or functionally obsolete categories. (366, or five percent, are structurally deficient; and 1,693, or 22 percent, are functionally obsolete.) The Washington transportation department's list of structurally deficient bridges is significantly smaller than the Research Information Program's figures.
Peterson said 25 percent of the state's bridges are functionally obsolete, 11 percent are structurally deficient and eight percent are fracture critical. "Functionally obsolete" means that an old bridge would be designed differently today to handle greater traffic. "Structurally deficient" means that its condition has deteriorated such that it cannot handle the loads it was originally designed to carry. "Fracture critical" means that a bridge section will collapse if a certain piece of its infrastructure fails.
Inslee and Peterson said the state has a good grasp of the conditions of its bridges. "The state of Washington does not lack in information,” said the governor. “We lack for resources."
The collapse of the I-5 Skagit River bridge has sparked renewed political jousting by state legislators, who are already deadlocked over whether and how to raise and spend the state's transportation budget.