After Years of Preparation, WSDOT Expands I-5 Northbound to Downtown Seattle

ByShannon J. Cortes

Mar 24, 2022

The Washington State Department of Transportation has been preparing us for more than a few years for this project: the widening of I-5 north to downtown Seattle. And this is the year it finally happens.

There was an overnight closure of I-5 northbound on Wednesday, and there will be another on Thursday. These are the construction opening moves that will add an additional 1,500 feet of lane through downtown Seattle.

All traffic will be diverted to the downtown collector-distributor lanes from 9 p.m. to 5 a.m. Thursday. WSDOT’s Tom Pearce said they needed the room to start moving the barriers to reduce the space for the new lane between Seneca and University Street.

“Just for the safety of the construction workers, sometimes we have to close the main tracks because they’re out there taking down barriers, building new barriers and re-striping so we have to have plenty of room for them to do it safely,” Pearce said.

The state is transforming the Seneca Street off-ramp from an exit-only lane to a optional exit and throughway. This will give drivers three northbound lanes passing under the Convention Center.

“Not merging people at the last second is really going to make a difference to the flow of northbound traffic,” Pearce said. “Everyone congregates there, especially when the expressways are southbound.”

Two lanes of passage will become three lanes of passage. Increased capacity – good for drivers.

The other part of this project might not be welcome, especially for drivers using westbound I-90 to northbound I-5. The state adds ramp counters to the collector-distributor pathwaysmeaning drivers heading northbound from I-90 to I-5, and those heading north from stadiums, will face managed lineups.

“We’re going to have two lanes on the collector-distributor with ramp meters, and then they’ll alternate traffic to keep the flow on the main line,” Pearce said. “It’s also going to give us more room to recover vehicles when we have backups.”

There will also be a new ramp counter from Cherry Street.

Drivers should be prepared for additional lane closures as this project progresses.

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