42nd Ave Bridge S Replacement Project

Project Status Update

We are currently collecting and analyzing data to establish existing conditions to inform preliminary design options for the 42nd Ave S bridge replacement.

Crews were onsite earlier this winter conducting survey, traffic data collection, marking environmental features, and geotechnical work. The measurements and research done by surveyors informs engineers of existing site conditions and property boundaries. Crews may return to the site for follow-up investigations. This work could include clearing vegetation, additional investigations may include additional drilling, environmental, hydraulic, or surveying.

The project team recently submitted a grant for federal funding available for maintenance or replacement of existing bridges, and will be pursuing additional grants throughout the year.


Project Overview

The 42nd Ave S Bridge is an important arterial for the City of Tukwila and surrounding communities. The bridge, designed in 1927 and built in 1949, is reaching the end of its design lifespan and needs to be replaced. The current 42nd Ave S Bridge consists of a 3-span 280-foot-long bridge with a sufficiency rating of 7.56 out of 100 and is considered both Structurally Deficient and Functionally Obsolete by the Federal Highway Authority (FHWA). The 2018 average daily traffic volume (ADT) was 10,300 vehicles per day.

A consultant team has been brought onboard by the City to develop a design for a replacement bridge. A component of the design work will involve gathering feedback from community stakeholders to guide portions of the design process. There will be multiple opportunities for the public to share their thoughts on bridge design and other project features.

To stay up to date on the project and learn about upcoming feedback opportunities, please sign up for the project mailing list below.


Join the Project Mailing List



The project is currently in the design phase which will continue through 2021.


Type/Size/Location (TSL) Report: A TSL report will consider all reasonable replacement options eligible for federal funding and help narrow the choices down to a preferred alternative. The report will determine the functional and physical characteristics of the bridge, how it will be construction, and its location. The consultant team need community input to inform the TSL report.


Frequently Asked Questions

What is the status of the 42nd Ave S Bridge?

The 42nd Ave S Bridge, constructed in 1949, has been monitored in accordance with federal requirements, and since 2015, has been the subject of concern and evaluation by Tukwila Public Works, King County, and the Washington State Department of Transportation. Currently, the 42nd Ave S. Bridge carries a sufficiency rating (SR) of 7.56 on a scale of 100 – this means that the bridge is in poor condition and in need of urgent replacement. Specific technical examples of the bridge’s deterioration include loss of shoreline protection, concrete cracking at the north pier, frozen bridge bearings, corrosion, pack rust, and impact damage on a fracture critical bridge.

The primary responsibility of city government is to uphold and protect public safety, including the maintenance of infrastructure. In Tukwila, we are committed to a safe, transparent, and orderly replacement of this bridge.


Where are we in the process of replacing the 42nd Ave S Bridge?

In November 2020, the City of Tukwila retained a consultant to advance the design phase for a new bridge that will replace the existing one on 42nd Ave S. We expect the final design will be completed in December 2023. At that point, the project will move into the construction phase. Currently, the goal is to begin construction in early 2024 and complete the project by the end of 2025.


Do you have an emergency plan in place in case the 42nd Ave S Bridge collapses? 

After dealing with life and safety issues of immediate concern, traffic would be rerouted as it was when the bridge was closed for inspection. Truck traffic would be routed over Steel Mill bridge and residential traffic would be routed onto S. 115th, as a longer-term fix is planned and implemented.

Emergency response in any jurisdiction takes several factors into account, including the cause of any major incident. Whether failure of any structure is caused by fire or flood or natural disaster, responders first on the scene of any emergency situation are trained professionals who help to alert and call into service the appropriate agencies, and identify expertise and equipment needed to be most effective in securing and protecting public safety. As a best practice in emergency management, any emergency response of this scale would be managed and coordinated in accordance with the direction of the Tukwila Emergency Manager, King County, and the State of Washington.


How are you going to mitigate impacts during construction of the bridge, both to traffic in the Allentown neighborhood and to amenities such as the Community Center and spray park?

City has hired a design consultant to design the 42nd Ave Bridge replacement. As part of this design, the consultant will evaluate traffic rerouting during the construction phase of the project.  If the reroute impacts the Tukwila Community Center, alternative temporary improvements can be made available during the time of construction to mitigate the impacts. More information on potential reroutes will be developed as the bridge design progresses and will be shared with the community. Furthermore, any construction impacts to the Tukwila Community Center will be rehabilitated to equal or better pre-construction conditions.


Why isn’t the City of Tukwila conducting an EIS for the 42nd Ave S Bridge?

The new bridge at 42nd Ave S will replace existing infrastructure and is not expected to have significant impacts requiring preparation of an EIS. However, environmental analysis is being conducted following applicable State Environmental Policy Act (SEPA) and National Environmental Policy Act (NEPA) procedures.

The City of Tukwila is committed to working with stakeholders as part of that process, including Allentown residents, local Tribes, Washington Department of Fish and Wildlife (WDFW), United States Fish and Wildlife Service (USFWS), United States Army Corps of Engineers (USACE), City of Tukwila Department of Community Development, Washington State Department of Transportation (WSDOT), US Coast Guard, Department of Ecology (DOE), Department of Archaeology and  Historic Preservation (DAHP), Department of Natural Resources (DNR), National Oceanic and Atmospheric Administration (NOAA) National Marine Fisheries Service.

Additional stakeholders for this project include grant fund partners such as the Washington State Department of Transportation, Puget Sound Regional Council, Transportation Improvement Board, the Freight Mobility Strategic Investment Board, utilities, community centers, business organizations, active transportation partners, nearby businesses and others.


What can you do about trucks speeding on the 42nd Ave S Bridge and through the Allentown neighborhood? And relatedly, can you do more to enforce weight/speed restrictions on the bridge?

The roads near and through Allentown, as well as heavily trafficked roads in many neighborhoods in Tukwila, are monitored to determine traffic patterns and usage. We have assigned a traffic engineer to begin evaluating the issues flagged by Allentown neighbors, most recently during the community Open House in July 2021. Our assessment includes collecting traffic data that will help us to identify issues with factors such as speed and weight limits, as well as solutions that could include safety measures like lighting, sidewalks, crosswalks, curbs, speed limits and enforcement, to help protect residents and drivers.


What other kinds of fundraising has the City undertaken to get funds for this project and a replacement bridge?

Since 2017, the City has been actively applying for grant funding for the 42nd Ave S Bridge Replacement Project. These grants are highly competitive, and the City was unsuccessful in receiving grant funds for this project until 2021.

The City has received $13.5 million in grant funding- $1.5 million from the Puget Sound Regional Council to complete the 100% design phase and move the project into construction by 2024, and $12 million from the Washington State Department of Transportation’s Local Bridge Program, which can be allocated for all project phases.

The City has also applied for congressionally directed funding from Congressman Adam Smith and Senator Patty Murray for the 42nd Ave S Bridge project. We are still waiting to find out if we will receive funding from these sources. The City is continuing to apply for local, state, and federal funds to support project costs.


Alternative Access Study Project

The City of Tukwila and BNSF conducted an access study in 2016, which proposed solutions for rerouting traffic. What has happened since 2016?

Timeline 2016 to Present

March 2016 ·         BNSF Access Study Open House (Tukwila Community Center and Online)
November 2016 ·       BNSF Intermodal Facility Access Study – Draft Alternative Screening Analysis Report November 28, 2016
December 2016 ·         Draft Study findings transmitted to City Council
March 2017 ·         City met with BECU to discuss their concerns with the Gateway Drive alternative
May 2017 ·         Notice of SEPA Application issued with comment period ending – June 2, 2017
August 2017 ·         Open House – Preferred Alternative Outreach -. August 17, 2017
March 2019 ·         Great Northern Corridor Coalition (GNCC) Meeting and Tour of the BNSF South Seattle Intermodal Facility. March 27, 2019
June 2019 ·         Transportation & Infrastructure Services Committee discussed project and sent to C.O.W.

·         Councilmembers toured BNSF facility

October 2019 ·         Councilmember Kruller toured BNSF facility with NLC’s Brittney Kohler
May 2021 ·         Transportation & Infrastructure Services Committee discussed next steps for the project, including moving forward with an Environmental Impact Statement (EIS). May 24, 2021.
June 2021 ·         Council approved moving forward with an EIS. June 14, 2021
July 2021 ·         Transportation & Infrastructure Services Committee discussed funding options for the EIS and hiring a term-limited Project Manager. July 12, 2021.
July 2021 ·         Public open house held to provide updates and address questions/concerns. July 14 2021

Does the City of Tukwila have a preferred alternative access option to reroute freight traffic?

The City has no preferred option for alternative access to BNSF’s facility. The Council approved moving forward with the Environmental Impact Statement (EIS) at the June 14, 2021 Committee of the Whole Meeting. An EIS must be conducted for the City to determine a preferred alternative to reroute the existing truck traffic. The EIS will include robust community outreach and opportunities to engage for all interested parties on potential alternatives for freight traffic.


Does replacing the 42nd Ave S Bridge impact community efforts to reroute freight traffic from S 124th St?

No. The work to replace the 42nd Ave S Bridge is a public safety project and has zero effect on the larger community effort to reroute freight traffic off of S 124th St. The City of Tukwila is committed to collaborating with the Allentown community regarding freight traffic through the neighborhood and that collaboration is an entirely separate effort from the 42nd Ave S Bridge replacement. Further, the City Council has directed staff to engage in an Environmental Impact Statement (EIS) process – a necessary step to determine a preferred alternative– to further evaluate alternatives for freight traffic on this route. The EIS process will have significant opportunities for community input.


What are the next steps for the Environmental Impact Statement (EIS)?

As of July 2021, the City is looking to hire a project manager to oversee the EIS to determine an alternative access route for existing truck traffic. The City will also hold monthly meetings with the Allentown community to provide updates on the EIS and hear firsthand about questions and concerns.


Staff outlines the following schedule:

3rd and 4th Quarter of 2021 Hire Term-Limited Project Manager
4th Quarter of 2021 Begin monthly progress meetings with the

Allentown Community

1st Quarter of 2022 Start Request for Qualifications process for EIS

consultant, select consultant, and bring contract

to Council for approval

2nd Quarter of 2022 Start the EIS
4th Quarter 2023 Complete the EIS and report to Council and the

Allentown Community


How is the Environmental Impact Statement (EIS) being funded?

City funds will cover the cost of the EIS.


The US Congress is considering spending trillions of dollars on infrastructure – has the City of Tukwila applied for those funds to reroute freight traffic?

The City has not applied for infrastructure funding to reroute traffic. The City must complete the EIS process in order to determine a preferred alternative and then begin design work before any such project would be a candidate for funding.


What is the role of BNSF in this process?

We anticipate that BNSF will be an engaged stakeholder in this process, and we are including them when we share information, where appropriate, including invitations to public meetings. As with the larger Allentown community, BNSF is an important stakeholder going forward regarding any conversations about rerouting freight traffic.

How can residents be involved in this process?

The City will begin regular, monthly meetings with the Allentown community in the fourth quarter of 2021.  Residents are encouraged to attend these meetings for updates. In addition, the City website will be updated as the different projects progress. Finally, the EIS for the truck reroute effort is a comprehensive analysis that includes several opportunities for public comment and the community is encouraged to provide comments.

Have you thought about developing a citizen task force about this issue?

The City has been working with the Allentown Advocates and will continue to work with them throughout the duration of these projects.



Project Library


Contact Information

For general project questions, please contact Adam Cox at 206-431-2446 or email