As we reported earlier this month when the Spokane Street Bridge to West Seattle reopened, SDOT removed the temporary bike lanes they constructed on 1st Ave S in response to the closure but kept the Duwamish Trail connection on W Marginal Way. Now the department has reaffirmed that trail connection is here to stay.

After extensively studying the impact of repurposing one lane along the west side of the street to create a two-way bikeway, SDOT found only positive impacts on traffic. Travel times increased by 2 seconds, but that is a good outcome because it is the result of a 12% decrease in average vehicle speeds from 43 mph (13 mph above the speed limit) to 37 mph (7 mph above the limit). This is a good reminder that bike lanes improve safety for all road users, including people in cars. It’s not a zero sum calculation where people biking get something at the expense of people driving. Safer roadway designs are better for everyone.

SDOT’s blog post about the project this week does not note an anticipated construction timeline for a final version of the bikeway, though it does confirm that the current bikeway will remain in place. And technically, it is not news that the lane is definitely happening since the department previously stated that they would build it “after the high bridge reopens in 2022.” But some members of the Freight Advisory Board have continued to resist the project, so it is good to hear that SDOT remains committed to it.

(As a side note, the Seattle Freight Advisory Board has not published their meeting minutes since February 2022, a seeming violation under Washington’s Public Meetings Act. So I cannot tell you what they said about the W Marginal Way bike lanes during their meetings, which is the whole point of the minutes requirement. Luckily, Ryan Packer has put in the persistent effort to cover the Board’s obscured meetings. Hopefully the new members can get their Board into compliance and improve public transparency.)

The trail connection has been needed for decades, but the most recent effort to build a bikeway on W Marginal Way came from two different places: Requests for safe crosswalks to the Duwamish Longhouse and the surprise closure of the upper West Seattle Bridge. In order to improve safety for people crossing the street to and from the Longhouse, SDOT restricted the width of the roadway by reducing southbound traffic to one lane. This project raised the question of why that lane reduction couldn’t be moved further north to create the bikeway. At the same time, the West Seattle Bridge closure led to big increases in traffic on W Marginal Way, exacerbating safety issues there. So a bikeway was proposed as a way to mitigate the new safety issues, but SDOT under Mayor Jenny Durkan unfortunately chose to delay the safety improvement until after the bridge reopened.

The time has come to finally complete the Duwamish Trail.