Highway 99 tunnel opens in Seattle — three years behind schedule

The long-awaited State Route 99 tunnel in Seattle opened over the weekend.

The double-decker underground highway opened 10 years after then-Governor Christine Gregoire chose a tunnel to replace the Alaskan Way Viaduct, an elevated freeway that had been damaged in 2006 by an earthquake. The viaduct carried around 90,000 vehicles daily.

“It’s going swimmingly so far,” said Port of Seattle spokesperson Peter McGraw, referring to the new tunnel. “People are trying it out and getting acclimated to the new route.”

The south end of the 1.7-mile tunnel starts in a neighborhood just south of downtown and adjacent to the Port of Seattle’s container ship terminal, which has a daily volume of about 1,000 trucks.

The north end exits in the South Lake Union neighborhood, where Amazon’s headquarters is located.

The tunnel is designed for motor vehicles, not pedestrians or bicycles. Freight is allowed with some restrictions.

Although the Port does not view the tunnel as a primary route for freight, the facility does see it as key to keep traffic flowing, McGraw said.

For that reason, the Port contributed $300 million to the project.

The tunnel, which cost $3.3 billion, was delayed for years after the mammoth machine (named Bertha after a local mayor)  boring the hole for the tunnel got stuck in place – for more than two years.

The saga of Bertha captivated and enraged the city, and added more than $500 million in cost overruns to the project. (Litigation is underway to determine who will pay the extra costs.)

This week’s grand opening coincided with a Seattle snowstorm that shuttered many schools and businesses. “So it was kind of hard to get an overall picture of traffic just yet,” McGraw said. “We are going to be keeping a close eye on it and making adjustments as necessary.”

Starting this summer, tunnel users will be assessed between $1 and $4.25 in tolls depending on the time of day.

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Linda Baker, Staff Writer

Linda Baker is a FreightWaves staff reporter based in Portland, Oregon. Her beat includes early-stage VC, freight-tech, mobility and West Coast emissions regulations.