Work to clear bumps along I-5 through downtown Seattle is expected to lead to months of weekend closures

ByShannon J. Cortes

Apr 21, 2022

The “bump brigade” is on its way. Workers are about to head back onto I-5 southbound in Seattle to remove all those terrible alignment-killing bumps left over from last year’s paving. But it will be expensive.

Why There Are Bumps Along I-5 Through Downtown Seattle

Sixteen working weekends: that’s what it will take to replace the 35 expansion joints on this stretch of I-5 southbound between downtown and the West Seattle Bridge. That will mean 16 weekends of full or partial I-5 closures essentially every weekend between May and September — depending on weather conditions — said Amy Moreno of the Washington State Department of Transportation.

“It will be every weekend except Memorial Day, University of Washington graduation, July 4, and Labor Day,” she said.

This is going to leave a dent in your travel plans all summer long, including going to matches in the stadium area and attending Seafair.

“We usually try to get around big events, but there’s just no getting around it,” she said. “It’s unfortunate because we don’t like putting people in these traffic jams, but to do this job and keep our contractor teams safe, that’s the type of lane reduction we need to do.”

It all starts on the weekend of May 6-8. Lanes will start closing Friday night and won’t reopen until early Monday morning. Moreno said all southbound I-5 drivers will be forced to use the collection and delivery lanes.

“It’s going to be slow,” she said. “People need to be prepared for this, and sadly it’s Mother’s Day weekend, but that’s no excuse – give your mom these gifts.”

This means that only one lane will cross the closure and return to southbound I-5 past the construction zone. When the WSDOT experienced similar shutdowns last year, backups expanded from the University District. We encourage you to delay your trip, use public transit, or choose an alternate route.

Why are parts of I-90 near Snoqualmie Pass so “groovy”?

It takes about 55 hours to chip and replace one of these expansion joints, then wait for the concrete to harden around them.

WSDOT replaces 35 of them, and it may be hard to believe, but most of them are original seals from when I-5 was first built.

“Thirty-two of the 35 are original,” Moreno. “They have been repaired several times by our maintenance crews, who have worked diligently over the years to keep them in running condition.”

This means that these seals have been around since the 1960s.

You might wonder why the state did the paving first, creating all these bumps in the process. WSDOT said it is easier to pour the concrete first and match the joints at that height than to match the concrete to the new joints.

The state is beginning this replacement work with the expansion joint that burst on April 1, causing a huge backlog for drivers.

So, that’s the end of the bumpy ride, but it’ll have to wait until September before those bumps go away.