I-5 Lid Feasibility Study

Downtown Seattle I-5 Lid Community-Building and Planning Studies  

What is the Downtown Seattle I-5 Lid Planning project?

We are leading a community-driven project to reimagine the I-5 corridor through downtown. Building on a grassroots movement, this visioning process explores ways to reconnect neighborhoods that have long been divided by the freeway and create a healthier, better connected, and more prosperous future for Seattle. 
 
The construction of I-5 during the 1950s and 1960s displaced homes, businesses, and communities, leaving many central Seattle neighborhoods divided for generations. Decades later, the freeway still affects nearby residents with pollution, noise, and physical barriers that limit access, connection and opportunity.

What's Happening Now?

In early 2025, we announced the authorization of $2.2 million in state and federal funding to develop a community vision for transforming the I-5 corridor through much of downtown Seattle. This next phase of planning will expand on the 2020 Lid I-5 feasibility study, which explored technical, economic and social considerations for building a “lid” over I-5.

Project Timeline

2010: A bold idea emerges
A community group called Lid I-5 came together around a big idea: finding ways to reconnect Seattle neighborhoods that were divided when I-5 was built through downtown. 
 
2020: Exploring what's possible
An early feasibility study took a closer look at the idea and found strong potential to bridge neighborhoods separated by the freeway. 
 
2023: Reconnection gains support 
Seattle City Council formally endorsed I-5 lid planning and directed City departments to pursue funding opportunities. 
 
2024: Investment in next steps
The project secured $2.2 million in federal and state funding to support planning, technical analysis, and community engagement. 
 
2026-2028: Shaping the future together
Community members will help shape a shared vision for reconnecting Seattle across I-5. The vision will guide future project phases such as planning, environmental review, design, and construction. 

How to Get Involved

The stories, values and priorities of people most affected by I-5 will help shape both the vision and the project's identity. Starting in late 2026, we will host community events to hear what matters most to people. Additional opportunities in 2027 will help shape a shared vision for reconnecting neighborhoods. Sign up for project updates to learn about ways to stay involved.  
 
Lid I-5 is a group of Seattle residents and volunteers that have been advocating for this project for over a decade. Visit the LidI5.org website to learn more about these important project partners.

I-5 Lid Feasibility Study (December 2020, Revised March 2021)

• Summary Report
• Economic and Financial Feasibility Memorandum
• Existing Conditions and Context Memorandum
• Real Estate Market Scan
• Technical Feasibility Memorandum
• Test Case Memorandum
• Department of Neighborhoods outreach report 

Committee Meetings

• Committee Work Session (December 11, 2019)
  • Agenda
  • Presentation
  • Workbook
• Preliminary Structural Feasibility Workshop (August 22, 2019)
  • Agenda
  • Presentation
  • Small group materials
    
  • Summary
• Guiding Principals and Key Study Assumptions Workshop (June 11, 2019)
  • Agenda
  • Presentation
  • Small group materials
  • Look-ahead
  • Work plan
  • Summary
• Orientation and Overview Meeting (March 26, 2019)
  • Presentation
  • Summary

Outreach

• I-5 Lid Outreach Report (August 2019)
• I-5 Lid Outreach Report (July 2019)

University of Washington Student Studies

• UW Department of Urban Design and Planning Study (New)
  Reconnecting the Emerald City - Analysis and Design Guidelines for the I-5 Lid
• UW Real Estate Finance Study
  Financing options for various lid scenarios developed by students of the University of Washington Runstad Center for Real Estate.