SEATTLE — All lanes of southbound Interstate 5 are now open near the Spokane Street Bridge in Seattle after crews made repairs to an expansion joint that came loose.
"Looking at the bridge on Spokane Street, they sort of dealt with the gap by bridging over it with a sheet of metal, like a metal plate, and that metal plate is bolted down on one side and it slides on the other side and that's what covers the gap which will open up," said UW Civil and Engineering Professor John F. Stanton.
Up to 10 vehicles either hit the broken expansion joint or crashed as a result of the incident Thursday night into Friday morning, according to the Washington State Department of Transportation (WSDOT).
One of the vehicles that hit the expansion joint rolled over in a crash, the WSDOT said. The driver of the vehicle suffered minor injuries.
The WSDOT first tweeted about the closure and repairs just before 3:15 a.m. All lanes reopened by 11 a.m.
There wasn't one specific cause of the expansion joint coming loose, according to WSDOT. Rather, time and wear and tear eventually led to the incident.
"Keep in mind, I-5 is an old Interstate," said WSDOT spokesperson Amy Moreno. "It was built in the 60's, it's aging, it was only meant to survive 25 years. Our WSDOT crews have done an admirable job of just trying to maintain it, but it is aging, and that's why we're doing this project.
"Unfortunately, there's wear and tear on those expansion joints, one of them popped early this morning, maintenance crews have gone out there and done a patch on it, but that's why we have to get out there and replace it now."
According to WSDOT, the Seattle section of I-5 was expected to last about 25 years before needing major work. Though it held up longer, by the mid-2010s major projects were necessary.
As part of the Revive I-5 project, WSDOT is replacing expansion joints between Spokane Street and I-90. Moreno said five have been replaced, with the rest to be replaced this summer. She encouraged drivers to follow WSDOT's social media channels to be aware of when fixes are being made.
"This is a two-year project and last year we went down, we put down the asphalt, and replaced five of the expansion joints," Moreno said.
WSDOT routinely inspects expansion joints, doing visual inspections driving over once a week and more thorough inspections below the bridge.
The life of a new expansion joint depends on the design and age of the road.
Expansion joints run across the width of the highway and allow sections of the roadway to “expand and contract with weather and to flex under the weight of heavy vehicles,” according to the WSDOT website.
The lane closures caused backups and delays for drivers during the Friday morning commute.
“We thank you for your patience, and for driving slowly and carefully around our work zone,” the WSDOT tweeted.
A project is currently underway to replace 56 expansion joints and repave over a mile of southbound I-5 between I-90 and Spokane Street. According to the WSDOT, the project began in May 2021, received $25.7 million in funding and is expected to be completed in the fall of 2022.
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