Information from Seattle Department of Transportation

We have an opportunity to align with our Vision Zero goals, keep goods moving, and promote sustainable travel options by building Phase 1 of the West Marginal Way SW Safety Corridor Improvements Project. 

Construction includes a permanent 0.4 mile of separated protected bike lane and safety measures for the driveway crossings along the Duwamish Trail.  The project improves safety and predictability for everyone, maintains freight priority on a major truck street, and continues the completion of the regional walking and biking network.

In 2020, Reconnect West Seattle survey respondents prioritized a West Marginal Way Protected Bike Lane (PBL) to encourage a multimodal option to travel to and from West Seattle during the closure of the West Seattle Bridge.  After initial outreach, the project was paused until the bridge reopened to reduce potential travel impacts along the detour route.

Over the last three years, we conducted thorough outreach and engagement to the community, businesses, freight, bike, and other interested stakeholders and collected data before and after the bridge reopened.  Findings show the project would have negligible impacts on the overall operations of West Marginal Way SW.  See SDOT’s blog for more information about the data and analysis.  Stakeholder feedback has been incorporated into the design and has resulted in enhanced safety measures for all travelers of West Marginal Way SW.

A temporary bike lane along West Marginal Way SW is currently in place, as it was being used as a detour route when the Spokane St Swing Bridge was closed in January for emergency repairs.  The protected bike lane will now be installed permanently along with driveway crossing treatments along the Duwamish Trail.  Construction is anticipated to begin in early April and will last approximately a month.

The West Marginal Way SW Safety Corridor Improvement Project increases awareness of driveways crossing the Duwamish Trail and separates people biking from driving for nearly half-mile by adding a protected bike lane (PBL).

The PBL is between Marginal Pl SW and the existing Duwamish Trail signalized crossing near SW Idaho St and closes a crucial gap in the regional walking and biking network. When complete, West Marginal Way SW will be a more predictable space for all travelers and speeds will be closer to the 30MPH posted speed limit.

Making West Marginal Way SW safer and more accessible for all travelers

WHAT TO EXPECT DURING CONSTRUCTION

We will be installing a 0.4-mile two-way protected bike lane (PBL) and striping on the western side of the corridor between SW Marginal Pl and Duwamish Longhouse and updating all 17 Duwamish Trail / driveway crossings on the east side of the corridor with signs and pavement markings.

In July 2021, we announced the construction of a new bike lane when the West Seattle Bridge reopened. Our approach to designing this project is data-driven and incorporates the input of the various travelers who use West Marginal Way SW. We collected traffic data multiple times, both before and after the West Seattle Bridge reopened and determined the project would have little to no travel time impacts, and positive safety effects for people walking and biking.

Construction starts in early April and is weather dependent.

Construction will be on a weekend for the bike lane and on both weekday and weekends for the Duwamish Trail driveway crossing treatments. Trail detours in short sections will be noted on signs. Please dismount bikes and walk around wet paint near driveways.

To learn more visit SDOT’s website, email or call us WestMarginalWay@seattle.gov or 206-400-7511.