Northbound I-5 project in downtown Seattle reaches milestone

By Amy Moreno

Drivers on northbound Interstate 5 near downtown Seattle might notice a return to an old driving layout. Crews closed the highway overnight on Wednesday, Feb. 15, to re-stripe back to the regular configuration between I-90 and Olive Way.

So why did drivers have to zig over a bit in the other pattern for the past few months? Crews started work in this area last year as part of a mobility project to add a third through lane and ramp meters to improve traffic flow. Construction dictated that traffic needed to shift so crews could install signs and wiring for the project.

Crews recently re-striped lanes on northbound I-5 in downtown Seattle, a milestone for this project that will improve travel through one of the state’s busiest areas.

This stretch of I-5 is a notorious chokepoint, even in the middle of the day on weekends. Creating more capacity to get vehicles through here is tough. I-5 is locked in through the heart of downtown Seattle with homes, businesses and city streets on both sides. We recognize that adding lanes doesn’t always solve traffic problems, so our team analyzes the “big picture” within our system, looking between the lines and outside for areas where it might make sense. Can traffic flow in a more efficient way? In this case, the answer is yes.

What seems like a conundrum turned into an opportunity for innovation for our engineers, who came through with this idea that works within our footprint and shifts barriers to create another through lane near Seneca Street. The plan includes meters to help traffic flow from I-90 and nearby ramps so mainline traffic doesn’t clog with that increased capacity.

This week’s re-striping is just the first milestone of many for this project. Coming attractions? Another lane through this stretch and ramp meters for the collector/distributor and at Cherry Street. Crews still need to finish electrical work, build sign bridges and install new traffic sensors and cameras. Finally, there will be one more reconfiguration and striping in late summer to make this improvement for mobility a reality.

If you don’t drive late at night through downtown, you might miss many of the lane reductions and construction involved in this project. These crews work hard, and this location, on the state’s busiest roadway, brings challenges to every aspect of this work. 

Crews prepare to hang new signs as part of the Seneca Mobility project

The work on this entire project should be completed later this summer, but this week, take a moment to enjoy the refreshed lines. When it comes to the road, the crews enjoy the satisfaction of those beautiful straight lines and the improved visibility that comes with them as much as drivers do. Behind the scenes, we’ll keep thinking “outside the lines” focusing on innovative ways to improve transportation.