I-405 interchange in Totem Lake entering final construction mode
Aug 15, 2023, 5:01 AM
(Graphic via the Washington State Department of Transportation)
It’s not to be easy to get into Evergreen Hospital in Totem Lake for the rest of August. Finishing touches on the new I-405 interchange at NE 132nd Street are going to cause some problems.
Nearly 18 months of work is already done, but now it’s time to put the final pieces in place just north of Kirkland on I-405. Workers are installing a new half-interchange at 132nd, providing direct access to the hospital and Juanita High School.
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Daily I-405 drivers know how rough this spot can be. The main interchange is at NE 124th Street, but there are on and off-ramps at NE 116th Street.
I-405 traffic manager Carl Westby said this current configuration makes it very difficult for drivers.
“If you’re trying to get to the 132nd corridor, a lot of people go down from the north, going down to 124th, backtrack, essentially do a u-turn to get there,” Westby said. “This is going to give them a direct route.”
There will be a ramp to 132nd from southbound I-405 and an on-ramp from 132nd to northbound I-405.
“I think we’re going to see a noticeable benefit at 124th when these ramps come online,” Westby said. “We’re going to have 400-500 trips an hour during the peaks that aren’t doing that backtrack movement and are going to just directly use the new half interchange.”
The new interchange is set to open in November.
“That’s really going to help with all the growth that’s occurring in that area,” Westby said.
But before those ramps can open, workers need to build two roundabouts to control traffic to and from the freeway.
“We’re going to have some closures leading up to Labor Day weekend, and after Labor Day, temporary roundabouts are going to come online,” Westby said. “Then later this fall, they will go into their permanent configuration with the new ramps coming online.”
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All of 132nd Street will be closed for two weeks under I-405 to accommodate this work. That closure begins Friday night and will last through Labor Day. Workers are also replacing a fish culvert there.
Some people have asked me why the state isn’t building a complete interchange there since it is already tearing things up. Westby explained that it was a matter of size.
“To fit a complete interchange north and south of there at 116th and 132nd simply won’t fit,” Westby said.
One of the reasons why there isn’t any room is because of the direct express toll lane ramp at 128th Street, which opened with the freeway expansion.
County planners expect the residential population of Totem Lake to double in size by 2035. This work should help ease some of that incoming congestion.