East Marginal Way Corridor Improvement Project

Updated November 18, 2021

What’s Happening Now?

RAISE grant - $20 million awarded to the East Marginal Way S Corridor Improvement project! 

After significant advocacy by local officials and advocates, U.S. Senator Maria Cantwell announced on November 16 that the East Marginal Way S Corridor Improvement project has been awarded $20 million from the U.S. Department of Transportation's Rebuilding American Infrastructure with Sustainability and Equity (RAISE) grant program. These funds will rebuild the roadway and help people safely drive, walk, and bike along the corridor to industrial and maritime jobs as well as employment sites in Downtown Seattle. Improving this busy multimodal corridor will also help accommodate larger and heavier truck traffic into the Port of Seattle and other maritime facilities.

The $20 million grant will help fully fund all work north of S Spokane St and allow us to start construction at the end of 2022. While this represents a delay for Phase 1 improvements, it allows us to build both the safety improvements and the road reconstruction at the same time - meaning fewer disruptions to traffic during construction. Project completion is estimated for 2025.  

This winter, we will be working on finalizing permits with the railroads and updating our plans to represent the combined improvements. We will follow up soon with the anticipated construction timeline and what to expect during construction.  

To read more about the RAISE grant and the improvements made by the East Marginal Way S Corridor Improvement project, read our blog announcement. Comments and questions are always welcome by emailing EastMarginal@seattle.gov or calling (206) 257-2263.

Stay connected

Visit our project library at the bottom of this page to read more about project features and schedule, review our federal grant proposals, and look at detailed design plans. Our project team is committed to keeping you informed. We will provide updates about new project information and ways to stay engaged throughout the year. Comments and questions are welcome by emailing EastMarginal@seattle.gov or calling (206) 257-2263.

Project Overview

As Seattle grows, improvements to freight mobility are essential to promote regional and international economic competitiveness. East Marginal Way is a major freight corridor that provides access to the Port of Seattle terminals, rail yards, industrial businesses, and between local Manufacturing and Industrial Centers (MIC's). It is also a designated Heavy Haul Route, critical last-mile connector, and vital route for over-sized trucks or those carrying flammable cargo. In addition, the corridor provides a major connection for people who bike between the West Seattle Bridge Trail, downtown, and the SODO neighborhood.

This project will:

  • Improve safety and reliability in the movement of people and goods

  • Support freight loads by rebuilding East Marginal Way S to heavy haul standards

  • Promote efficiency through signal modifications, improving wayfinding and lighting, and intelligent transportation systems

  • Improve safety by separating non-motorized modes of traffic from vehicle traffic  

Click here to view the 60% design overview.

East Marginal Way Segments

North Segment

For the North Segment (S Atlantic St to S Spokane St), design includes:

  • Protected bike lane separating non-motorized modes from freight traffic on the east side of East Marginal Way S between S Atlantic St and S Spokane St

    • The bike lane will be physically separated from the roadway by either a concrete barrier or landscaping and distance

    • Closer to S Atlantic St, the bike lane will move far from the roadway and be located under the SR-99 viaduct

  • Multi-use path on the west side of the street between S Horton St and S Spokane St

  • New signalized diagonal bicycle crossing at East Marginal Way S and S Horton St

  • Reconstructing the East Marginal Way S roadway to heavy haul standards from approximately S Massachusetts St to S Spokane St

  • Replacing the existing water main in areas where the roadway will be reconstructed north of S Horton St

  • Rebuilding the sidewalk on the west side of East Marginal Way S adjacent to the roadway reconstruction north of S Horton St

  • Rebuilding the intersection and existing traffic signal at East Marginal Way S and S Hanford street

  • Redesigning driveway at Terminal 25 South to improve visibility for people biking and driving

North Segment cross section.East Marginal Plan View - Hanford Options

PBL crossing at S Hanford StEast Marginal Plan View - Hanford Horton Options
PBL crossing at S Horton St

These recommendations are based on the public's desire to reduce conflicts between bicyclists and trucks accessing Port of Seattle driveways and are consistent with existing northbound bike flow. Our design team evaluated placing the diagonal crossing at S Hanford St to take advantage of the existing traffic signal, however our analysis shows less delay for all users if we create a new signal at S Horton St.

Central Segment

Central Segment

This project aims to provide a clear route through the confusing area between S Spokane St and Diagonal Ave S.

Our proposed design includes a shared use path on the east side of E Marginal Way S south of S Spokane St. At approximately mid-block, the path will cross to the west side of the street at a marked crosswalk, where it will continue to Duwamish Ave S. From Duwamish Ave S, people walking and biking will use a marked crosswalk to continue on the west side of E Marginal Way S past the concrete plant. This would mark the beginning of a multi-use pathway heading south.

Freight improvements proposed in the central segment include reconstructing the surface street of E Marginal Way S to heavy haul standards, improving wayfinding and lighting to make it easier to navigate the area, and ITS improvements including a Dynamic Message Sign at S Alaska St.

Proposed central segment improvements

South Segment

South Segment

The South Segment (Duwamish Ave S to 1 Ave S) is part of SR 99. There are neither bike facilities nor sidewalks on the west side of the street, and some missing sidewalks on the east side. These factors contribute to a challenging walking and biking environment for people trying to move through the area. 

In March 2018, SDOT completed a preliminary design for this section that included:

  • Pedestrian improvements at each existing traffic signal
  • Constructing missing sidewalks on the east side of the street
  • Transit stop improvements
  • Signal enhancements where appropriate to improve predictability and safety for people walking and biking

We have developed a proposal to improve the connection to the 1st Ave bridge, however funding constraints will prevent this from being part of the core project scope. If we identify a grant opportunity that allows us to include this connection, we will do so.Design and construction of this portion of the project is currently unfunded. We will continue pursuing funding opportunities to advance the South Segment but currently do not have a schedule for this portion of the project.Initial analysis of this section of the project also included evaluation of whether a lane of traffic on SR 99 could be removed to allow construction of a protected bike lane, as called for in the Seattle Bicycle Master Plan. Due to traffic volumes on SR 99, removing a motor vehicle lane was not recommended.

East Marginal Map South Segment
Click to enlarge


  • Safety - Improved access and multimodal connections for all corridor users. Separated facilities for people walking and biking to reduce potential conflicts.

  • Freight mobility - Support the economic vitality of our region by making it easier for freight to access the Port of Seattle and local industrial businesses.

  • Efficiency - New and updated facilities for people walking and biking will improve access for transit. Signal modifications and intelligent transportation systems (ITS) will optimize travel for all corridor users.


Funding to evaluate alternatives and complete early design is provided by the 9-year Levy to Move Seattle, approved by voters in 2015. Learn more about the levy at Levy to Move Seattle. In 2019, we secured grants to complete full design for the north and central segments, and to begin Phase 1 construction.



  • Data collection
  • Early design workshops
  • Preliminary traffic analysis


  • Online Open House and Survey from Spring to Summer
  • Spring
    • Develop options
    • Seek input on options
  • Summer
    • Create preliminary engineering designs
  • Fall
    • 10% design complete


  • Winter-Spring
    • 30% design complete


  • Complete project design

Fall 2022

  • Begin Phase 1 construction

Phase 1 Schedule Graphic

Graphic of the project timeline

Community Engagement

We are currently advancing design based on public input and comment collected from 2015 to present. In fall 2019, we worked with businesses in the Central Segment to develop a preliminary concept for the area. We will continue working with businesses and community groups to develop design.To request a briefing for your organization or for more information, please send an email to EastMarginal@seattle.gov.

Project Materials

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