Two-mile-long tunnel part of replacement for Seattle’s seismically vulnerable Alaskan Way Viaduct

From a major earthquake to a massive machine that churned through two miles of soil, the path to the new State Route 99 tunnel in Seattle was long and winding. But when the sun rises on Monday morning, it will be a straight shot between the Space Needle and the stadiums for travelers, and a new day for Washington state’s transportation system.

“Today, we can say we’ve forged a new path,” said Gov. Jay Inslee. “From Jimi Hendrix to Bertha Knight Landes, our state’s history is filled with examples of ingenuity and perseverance. The opening of this tunnel is further proof that we can overcome big challenges and create lasting change in our communities.”

The Washington State Department of Transportation will open the new tunnel early Monday, Feb. 4, bringing to an end the three-week #Realign99highway closure. The tunnel will provide travelers a direct route under downtown with new entrances and exits at each of the tunnel portals located at the north and south ends of downtown.

“This is a game changer,” said Transportation Secretary Roger Millar. “Our number one goal was to remove a vulnerable structure from our highway system. Along the way we reshaped a major transportation corridor that is a key component of the multimodal transportation system we and our partners are building for the Puget Sound region.”

Crews will begin opening the tunnel in the early hours of Monday, Feb. 4. The new structure will open ramp by ramp over the course of several hours. The tunnel will be fully open by the time travelers hit the road for the morning commute. 

After the tunnel opens

Traffic patterns are expected to change after the tunnel opens. These videos illustrate how to get around the new street network. 

Although the tunnel will open to traffic on Monday, the new northbound off-ramp to Alaskan Way at the south portal won’t open for one to two weeks after the tunnel. That’s especially important for travelers approaching downtown from the south. 

Until the ramp opens, the last exit for travelers on northbound SR 99 before the tunnel is at South Spokane Street. The next available exit is at the north portal, near Seattle Center.

Buses that used to travel on the viaduct will continue their reroute until the ramp opens. Visit King County Metro for additional information about transit service.

Millar said WSDOT will continue to coordinate closely with partner agencies to monitor traffic conditions and make adjustments as needed. He also encouraged travelers to consider sticking with alternative commute choices they may have adopted during the closure.

“People really stepped up and did their part during this closure,” Millar said. “We’re hoping that people discovered new ways to get around over these past few weeks, and that they’ll be willing to keep it up. When more people make smart commuting choices, it makes it easier for all of us.”