It started in 2014 with the West Seattle Transportation Coalition‘s list of priorities. In January 2015, when then-City Councilmember (and West Seattle resident) Tom Rasmussen chaired the council’s Transportation Committee, he announced a West Seattle Bridge Corridor Management Task Force; in September 2015, he presented a “whitepaper” with recommendations.

Some have been put into place.

Last year, the council got a progress report, and asked SDOT to study four possibilities for addressing congestion factors, as noted in the last paragraph of District 1 City Councilmember Lisa Herbold‘s update here.

Now, the results of that request are out, in the form of SDOT’s “West Seattle Bridge Corridor Congestion Management Study,” made public by Councilmember Herbold. (If you can’t read it in the embedded version above, here it is in PDF.)

It addresses goals for the upper bridge and lower roadway – not just the low bridge, but the entirety of lower Spokane Street all the way east to Airport Way.

For the upper bridge, the goal is to reduce crashes, improve responding times when they do occur, and “improve operations capability on alternate routes.” The report says 50 crashes happen each year, on average, on the upper bridge.

For the lower corridor, the goal is to “manage a roadway that experiences frequent and unpredictable disruptions as the ‘normal’ operating condition,” and managing truck queues on Spokane St. The report notes averages of five 12-minute low-bridge openings each day. The report notes the “federal mandate” for maritime traffic to maintain priority and does not recommend “restricted opening hours” for the bridge. (However, the recommended Duwamish Waterway User Group might discuss voluntary limits, the report says.)

Also noted: A daily average of 67 train crossings between 1st and 4th on Spokane. And it acknowledges the low bridge/roadway as “the only pedestrian and bicycle train connection” between West Seattle and SODO, with connections to downtown.

The recommendations, in descending order of their estimated costs:

*Enhance alternative routes (to change traffic flow during incidents) via ITS – $6.6 million

*Smart traffic signals and ITS for Spokane St. – $6 million

*Active Traffic Management System on the high bridge – $5.4 million

*Construct Refuge Pullouts – $2.5 million for one, $5 million for two

*Swing Bridge Delay Information System – $950,000

*24/7 traffic-operations center for SDOT to get information out – $875,000

*Rail Crossing Delay Information System – $600,000

*Raised pavement/striping – $250,000

*Establish Duwamish Waterway User Group ($0)

*Terminal 5 Queue Management System and Port/City agreement to ban truck backups on Spokane St. ($0)

The Active Traffic Management System would include “overhead signs capable of posting advisory speeds, variable speed limits, and warning messages approaching backups or queues at targeted locations. … This would be similar to the system installed on I-5.”

Refuge Pullouts would be spots where responders could “push disabled vehicles or vehicles involved in collisions … to restore traffic in the corridor.”

The Swing Bridge Delay Information System and Rail Crossing Delay Information System would involve adding cameras and messaging signs that would include countdowns for how much longer conditions might last.

Not recommended: “Median gates” that could be used to facilitate U-turns on the high bridge if a serious incident led to a blockage. They wouldn’t improve response times or safety. Also not recommended, striping a “fire lane” on the high bridge; this is a longrunning practice in New York City but those researching for the West Seattle Bridge Corridor Report were told they weren’t a good idea for various reasons.

The study includes an extensive discussion of what might happen when “modernized” Terminal 5 reopens, regarding truck backups. We’ll take a look at that in a separate report. Meantime, Councilmember Herbold says that regarding the suggested actions, “I’ll be looking for ways to work with SDOT to implement these recommendations.”