Viadoom in Seattle

Planned and unplanned EOC activations.

by Eric Holdeman / December 21, 2018

Here in the greater Seattle area, we are nearing the end of the Alaskan Way Viaduct, a two-tiered roadway that looks exactly like and modeled on the roadway that collapsed in the 1989 Loma Prieta Earthquake in San Francisco. 


The Seattle structure was damaged in the 2001 Nisqually earthquake, and here in Washington state and Seattle, the debate raged for years on how best to replace the structure — surface street, cut and cover tunnel, deep bore tunnel, etc. The deep bore tunnel won out:


Now it is time to close the viaduct and make the connections to the tunnel. That will require a three-week (minimum) no-viaduct, no-tunnel time period. Yikes! Commute times via car from the south are expected to double. So, my 2.5 hour commute today (in a car) would double to 5 hours — one way. I will not be driving to work — taking the train.  And, on the train, I'm the second stop coming from the south and I expect I may have to stand for the 40-minute trip. It will be ugly, to say the least.

You can read my notes from a briefing yesterday at the Seattle Emergency Operations Center (EOC). Some of the locations will mean nothing to folks outside of the Puget Sound — unless you have taken an Alaskan cruise out of Seattle. Besides the information below I offered several thoughts at the meeting. They need to message people to fill up their gas tanks before attempting a commute into the city. There are far and few gas stations in downtown Seattle. 75 percent of the people who work and live in Pierce County, south of Seattle (where I live) have jobs in King County (where Seattle is). I also suggested stationing Porta-Potties on the roadways ... I'm just saying it is a long wait to get into Seattle. I also noted to the group getting briefed that is is a small sample for what an earthquake in Seattle will do to traffic. I pointed out the other elevated structure is Interstate 5 southbound out of Seattle for a mile or so, until you get to the old Rainier Brewery. 

I also mused separately, what might a Seattle Mayor disaster proclamation say — if one was needed? Are there any emergency powers that the mayor could use to make the situation better?

Which brings me to activating the EOC. Typically we end up having no-notice events that happen and that we have to react to. Sometimes, Y2K for example, there is time to prepare and you activate in advance of the event — just in case. I will be watching with great interest how on Jan. 11 (first day of closure) rolls out and then the days after that. I expect many people will be taking a "wait and see" attitude on the 11th — delaying and cancelling any commuting, but eventually, people will have to make a physical trip to work. 


Seattle DMC
20 December 2018
Realignment of Viaduct to Tunnel


SDOT presentation

The three week no route available is not the end of the project. March 2019 will include buses out of the tunnel.

85,000 new residents in the last two years to King County.

Tear-down of the viaduct will also be an issue for months.

Key Arena Construction…

They are working:

• Monitor and manage
• Invest in transit
• Reduce number of single vehicle trips
• Managing the public right of way.
• Communicating with the public

The tunnel is ready, the enter and exit points need to be worked. Jan. 4 some impacts at night for on/off ramps by stadiums. Minimum of three weeks. Feb. 4 is the earliest it will open. Not a guarantee — weather dependent.

Closure begins at West Seattle Bridge and up to Battery Street Tunnel

90,000 vehicles on HWY 99 today. Impacts to I-5, 405.

Trips are expected to start earlier and end later. Expect commute times to double.

When the tunnel opens, new routes. No on and off ramps in DT Seattle. Surface streets to get into Seattle.

The new Alaskan Way will be needed to help. Construction will start in this summer and last two years. ☹

South Dearborn Street exit off of 99 will take you into Seattle. Does not exist — part of the construction.

6th Ave in the North will feed the Tunnel.

Viaduct removal will take six months. Will start almost immediately. Alaskan Way will go from four lanes to two when the viaduct is coming down.

The Battery Street Tunnel will take two years to fill with material from the viaduct.

Aurora buses will be impacted by North Portal area work, routes include E, 5 %x, 26, 28

Freight routes during #realign99closure

South Portal and SoDo will feel the impact. Significant traffic expected to be diverted to those areas.

They will be extending transit priority hours on 3rd Ave, 6AM to 7PM.

Modify and schedule permitted construction work for maximum ravel capacity; temporarily restrict parking

Regionally collaborate on a regional communications and outreach effort, including community meetings with businesses and community groups

Employers promoting flex time and working remote. will have updates twice daily.

Plan B: Implement if needed

• Make additional signal modifications
• Increase on-street parking restrictions
• Add transit-only lanes
• Operate streets as transit-only
• Re-route transit to less congested routes
• Modifying I-5 Ramp availability and signal timing
• Restrict turns…

City of Seattle OEM

City EOC will not be activate, SDOT Transportation Operations Center (TOC) will be 24/7. Two 12-hour teams. Changing shifts noon and midnight. They may adjust individual schedules so maybe people only come in at 5AM.

The EOC will do two conference calls each day, 10:30AM and 7:00PM. Basically an information sharing call.

• Coordinate actions and resources to maximize the flow of traffic
• Ensure the delivery of City emergency services and other City services
• Manage the needs of the City workforce to ensure seamless internal operations
• Ensure coordinated and consistent messaging with city employees and external stakeholders


Summary: Watch the national news on Jan. 11 — I fully expect that some mention of Seattle and Viadoom will be made.

It would make a terrific 60 Minutes segment at some point in the future.

Did I mention that a totally new guy is taking over as the Seattle Department of Transportation director? I guess he can't be blamed for the planning for the closure should it all go to Hell in a handbasket. I'm wondering if he will be confirmed and in place before the closure? He might want to be on a "transitional vacation" in Hawaii on Jan. 11.