Thornton Creek Bridge Study

Updated February 2020

What's Happening Now?

Thanks to those of you who provided feedback throughout this process. Comments and suggestions from the community informed the development of the conceptual design alternatives.

Currently, we're funded only through 30% design. This planning study will be used to help the City of Seattle plan for the funding needed for future bridge replacements.

Study Background

Over an 8-month period, bridge alternatives were evaluated considering multimodal transportation needs, short- and long-term residential impacts, waterflow capacity, environmental impacts, bridge maintenance, and cost. Based upon these criteria, replacement is the most feasible option for all 4 bridges.

Project Overview

In 2019, we studied 4 bridges that cross the Thornton Creek Channel:

Bridge 105 is on NE 110th St, 200 feet east of the intersection with 35th Ave NE

Bridge 105 on NE 110 St

Bridge 115 is on 39th Ave NE, 120 feet north of the intersection with NE 105th St

Bridge 115 on 39th Ave NE

Bridge 104 is on NE 105th St, at the intersection of 40th Ave NE

Bridge 104 is on NE 105th St

Bridge 109 is on 45th Ave NE, 70 feet south of the intersection with NE 97th SE

Bridge 109 is on 45th Ave NE

Various experts visited each bridge to study its current condition and wrote a report detailing their findings. These experts examined many factors, including the structure of the bridges, the condition of the soil beneath them, the flow of the creek, and the potential environmental impacts of any work. We completed this study to 30% design in February 2020.

Project Location

Map showing thornton creek and the four bridge locations


This study has been funded through early planning. Funding for design and construction will be evaluated following a review by the Levy to Move Seattle Oversight Committee.

Thornton Creek Bridge Study Outreach

Community outreach design event

Date Event
February 28, 2020                        Tabling event for the public - Meadowbrook Community Center
February 27, 2020                        Briefing for Meadowbrook Community Council and Thornton Creek Alliance - Meadowbrook Community Center
September 10, 2019                        Briefing for Meadowbrook Community Council - Meadowbrook Community Center
August 21, 2019                        Open House - Saint Anne Nursing and Rehabilitation Center
August 20, 2019 Open House Meadowbrook Community Center
August 8, 2019 Invite Mailer
April, 2019 Door to door outreach

Materials - Planning Phase

Get Involved

We're committed to working with all project neighbors and stakeholders. If the Thornton Creek Bridges Study advances to the next phase, we'll reach out and keep you informed. To sign up for email updates on the project, please contact our communication lead, Darrell Bulmer at


Greg Spotts, Director
Address: 700 5th Ave, Suite 3800, Seattle, WA, 98104
Mailing Address: PO Box 34996, Seattle, WA, 98124-4996
Phone: (206) 684-7623

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The Seattle Department of Transportation (SDOT) is on a mission to deliver a transportation system that provides safe and affordable access to places and opportunities for everyone as we work to achieve our vision of Seattle as a thriving, equitable community powered by dependable transportation.