Help Decide the Future of the Burnside Bridge
January 22 - February 23, 2021
This online open house and survey for the Earthquake Ready Burnside Bridge are closed currently. Please join our mailing list to stay up-to-date. We’ll let you know about future opportunities to share your thoughts about the project.
A New Burnside Bridge
Why are we replacing the Burnside Bridge?
Portland’s aging downtown bridges are not expected to withstand a major earthquake. That’s why Multnomah County is taking the lead on making at least one crossing earthquake ready.
A resilient Burnside Bridge will help our community recover after a major earthquake and provide a long-term river crossing that supports our transportation needs for the next century.
How did we get here?
Over 100 options were studied during this project’s Feasibility Study Phase (2016-2018), including tunnels, ferries, double-deck bridges, and other bridge options. From that study, four bridge alternatives were recommended for further evaluation in the Environmental Review Phase . In fall 2020, after a robust evaluation process and gathering input from the public, the Replacement Long Span was recommended as the Preferred Alternative for the Draft Environmental Impact Statement because it is the most seismically resilient with the lowest cost and fewest impacts to natural resources. Long span bridges have fewer columns in the ground but more structure above the deck. This helps avoid higher construction costs and risks associated with building in the unstable soils that surround the Burnside Bridge.
Burnside Bridge: Located on a Key Lifeline Route
Located in the heart of downtown and on a regionally established lifeline route, Burnside Street is one of the most reliable earthquake emergency routes. It has the fewest structures on, over, or connected to it that are vulnerable to collapse during an earthquake. Red dots illustrate vulnerable structures in the map below.
The following interactive map displays emergency transportation routes in the Portland Area. For a full-screen version, click the arrows located at the upper right. Use the navigation tools at the lower right to explore the map. View legend information at the lower left.
Emergency Routes in the Portland Metro Region
Where are we now?
An important next step in the process is to select the type of long span bridge to build. The options being considered include a Tied Arch (like the Fremont Bridge), a Cable Supported (like the Tilikum Bridge) and a Truss (like the Hawthorne Bridge).
This also includes the type of movable span. The options being considered include Bascule (like the Burnside Bridge) and Lift (like the Steel Bridge).
Photo Credits: Tony Webster and TriMet
Photo Credit: Chris Yunker
It’s helpful to think of the bridge as three bridges in one, with the west, middle and east sections offering different features and tradeoffs to consider in the evaluation process.
Your Input is Important
We are studying several different bridge types and variations. We invite you to review them below and share your thoughts. Your feedback will be used to help inform the selection process.
A committee of design professionals and the Community Task Force have reviewed a broad range of bridge types and dismissed several types due to significant engineering challenges. The range of feasible types presented here are now being recommended for further evaluation. Please review the options below and answer survey questions at the end.
As you review, it’s important to consider the trade-offs among options. For example, what effects do above-deck features have on under-bridge features and experience? Your input will inform the future of Burnside Bridge!
Watch this video! The interactive, 360-degree video below provides an overview of the options.
For a 360-degree experience, use your mouse to click around within the video and move the screen.
Earthquake Ready Burnside Bridge: A 360 View of Bridge Type Options
Possible Bridge Types
Option 1 – Tied Arch
The Tied Arch long-span bridge style has curved arches above the deck with thin cables inside the arches.
Option 1A – Tied Arch with Bascule
This variation has a Tied Arch on both the west and east spans with a Bascule style movable span in the middle that opens and closes to allow for boats to pass through.
Key Features
- Places columns at the eastside of Naito Parkway, limiting sightlines into Waterfront Park, but creating more open space in the middle of the Park
- Bascule movable span has less above deck structure than the lift movable span but is more costly
Option 1B – Tied Arch with Bascule and West Girder
This variation has a Tied Arch on the east, a Bascule movable span in the middle and a Girder style span on the west.
A Girder span allows for the removal of above-deck structure by thickening the deck and adding a row of columns. This is being studied in response to expressed interest in more open views on the Burnside Bridge; however, this comes with the tradeoff of columns in the middle of Waterfront Park and a lower ceiling height (or vertical clearance). A girder is not being considered for the east span because it is not feasible – learn why in the Frequently Asked Questions document.
Close-up of Girder in Waterfront Park (north side)
Key Features
- West Girder places columns in the middle of Waterfront Park, opening sightlines into the park but limiting open space in the middle of the Park
- West Girder has a thicker deck, reducing the ceiling height by about 6-8 feet from what it is today. This creates more shadows and reduces the amount of natural light under the bridge; however, it allows for unobstructed city views above the deck.
- West Girder has no above deck structure, allowing for unobstructed views from the bridge
- West Girder is less expensive than the Tied Arch, Cable Supported, and Truss options
- Bascule movable span has less above deck structure than the lift movable span but is more costly
Option 1C – Tied Arch with Lift
This variation has a Tied Arch on both the west and east spans with a Lift style movable span in the middle to allow for boats to pass through.
Key Features
- Places columns at the east side of Naito Parkway, limiting sightlines into Waterfront Park but creating more open space in the middle of the Park
- Lift movable span has vertical towers towards the middle of the bridge, smaller in-water piers, and is less costly than the Bascule movable span (the lift movable span can come with an arch or without)
Option 1D – Tied Arch with Lift and West Girder
This variation has a Tied Arch on the east, a Lift movable span in the middle and a Girder style span on the west.
Key Features
- West Girder places columns in the middle of Waterfront Park opening sightlines into the park but limiting open space in the middle of the Park
- West Girder has a thicker deck, reducing the ceiling height by about 6-8 feet from what it is today. This creates more shadows and reduces the amount of natural light under the bridge; however, it allows for unobstructed city views above the deck.
- West Girder has no above deck structure, allowing for unobstructed views from the bridge
- West Girder is less expensive than the Tied Arch, Cable Supported, and Truss options
- Lift movable span has vertical towers towards the middle of the bridge, smaller in-water piers, and is less costly than the Bascule movable span (the lift movable span can come with an arch or without)
Option 2 – Cable Supported
The Cable Supported long-span bridge style has a triangle-like shape created by using tall support towers with long cables coming down to the deck. (Cable Stayed and Extradosed bridges are examples of this type.)
Option 2A – Cable Supported with Bascule
This variation has a Cable Supported span for both the west and east spans, with a Bascule- style movable span in the middle that opens and closes to allow for boats to pass through.
Key Features
- Places columns in the middle of Waterfront Park opening sightlines into the park compared to the Tied Arch and Truss but limiting open space in the middle of the Park
- Bascule movable span has less above deck structure than the lift movable span but is more costly
Option 2B – Cable Supported with Bascule and West Girder
This variation has a Cable Supported span on the east, a Bascule movable span in the middle, and a Girder style span on the west.
A Girder span allows for the removal of above-deck structure by thickening the deck and adding a row of columns. This is being studied in response to expressed interest in more open views on the Burnside Bridge; however, this comes with the tradeoff of columns in the middle of Waterfront Park and a lower ceiling height (or vertical clearance). A girder is not being considered for the east span because it is not feasible – learn why in the Frequently Asked Questions document.
Close-up of Girder in Waterfront Park (north side)
Key Features
- West Girder places columns in the middle of Waterfront Park opening sightlines into the park but limiting open space in the middle of the Park
- West Girder has a thicker deck, reducing the ceiling height by about 6-8 feet from what it is today. This creates more shadows and reduces the amount of natural light under the bridge; however, it allows for unobstructed city views above the deck.
- West Girder has no above deck structure, allowing for unobstructed views from the bridge
- West Girder is less expensive than the Tied Arch, Cable Supported, and Truss options
- Bascule movable span has less above deck structure than the lift movable span but is more costly
Option 2C – Cable Supported with Lift
This variation has Cables on both the west and east spans, with a Lift-style movable span in the middle to allow for boats to pass through.
Key Features
- Places columns in the middle of Waterfront Park, opening sightlines into the park compared to the Tied Arch and Truss but limiting open space in the middle of the Park
- Lift movable span has vertical towers towards the middle of the bridge, smaller in-water piers, and is less costly than the Bascule movable span
Option 2D – Cable Supported with Lift and West Girder
This variation has a Cable Supported span on the east, a Lift movable span in the middle, and a Girder-style span on the west.
Key Features
- West Girder places columns in the middle of Waterfront Park opening sightlines into the park but limiting open space in the middle of the Park
- West Girder has a thicker deck, reducing the ceiling height by about 6-8 feet from what it is today. This creates more shadows and reduces the amount of natural light under the bridge; however, it allows for unobstructed city views above the deck.
- West Girder has no above deck structure, allowing for unobstructed views from the bridge
- West Girder is less expensive than the Tied Arch, Cable Supported, and Truss options
- Lift movable span has vertical towers towards the middle of the bridge, smaller in-water piers, and is less costly than the Bascule movable span
Option 3 – Truss
The Truss long-span bridge style has an enclosed above-deck structure that uses thick diagonal and vertical beams.
Option 3A – Truss with Bascule
This variation has a Truss on both the west and east spans, with a Bascule-style movable span in the middle that opens and closes to allow for boats to pass through.
Key Features
- Places columns at the eastside of Naito Parkway, limiting sightlines into Waterfront Park but creating more open space in the middle of the Park
- Has the most obstruction to on-bridge views compared to the other two options and is the most expensive long-span type to maintain
- Bascule movable span has less above deck structure than the lift movable span but is more costly
Option 3B – Truss with Bascule and West Girder
This variation has a Truss on the east, a Bascule movable span in the middle, and a Girder-style span on the west.
A Girder span allows for the removal of above-deck structure by thickening the deck and adding a row of columns. This is being studied in response to expressed interest in more open views on the Burnside Bridge; however, this comes with the tradeoff of columns in the middle of Waterfront Park and a lower ceiling height (or vertical clearance). A girder is not being considered for the east span because it is not feasible – learn why in the Frequently Asked Questions document.
Close-up of Girder in Waterfront Park (north side)
Key Features
- West Girder places columns in the middle of Waterfront Park opening sightlines into the park but limiting open space in the middle of the Park
- West Girder has a thicker deck, reducing the ceiling height by about 6-8 feet from what it is today. This creates more shadows and reduces the amount of natural light under the bridge; however, it allows for unobstructed city views above the deck.
- West Girder has no above deck structure, allowing for unobstructed views from the bridge
- West Girder is less expensive than the Tied Arch, Cable Supported, and Truss options
- Bascule movable span has less above deck structure than the lift movable span but is more costly
Option 3C – Truss with Lift
This variation has a Truss on both the west and east spans, with a Lift style movable span in the middle to allow for boats to pass through.
Key Features
- Places columns at the eastside of Naito Parkway, limiting sightlines into Waterfront Park but creating more open space in the middle of the Park
- Lift movable span has vertical towers towards the middle of the bridge, smaller in-water piers, and is less costly than the Bascule movable span (the lift movable span can come with a truss or without)
Option 3D – Truss with Lift and West Girder
This variation has a Truss on the east, a Lift movable span in the middle, and a Girder-style span on the west.
Key Features
- West Girder places columns in the middle of Waterfront Park, opening sightlines into the park but limiting open space in the middle of the Park
- West Girder has a thicker deck, reducing the ceiling height by about 6-8 feet from what it is today. This creates more shadows and reduces the amount of natural light under the bridge; however, it allows for unobstructed city views above the deck.
- West Girder has no above deck structure allowing for unobstructed views from the bridge
- West Girder is less expensive than the Tied Arch, Cable Supported, and Truss options
- Lift movable span has vertical towers towards the middle of the bridge, smaller in-water piers, and is less costly than the Bascule movable span (the lift movable span can come with a truss or without)
Topics to Consider
To help decide which bridge types to build, we will evaluate each option on the following topics:
Human Experience & Bridge Surroundings
- On-Bridge Experience: How well does the option provide benefits to people when they are on the bridge?
- Below-Bridge Experience: How well does the option provide benefits to people when they are under the bridge (in areas such as parks, roads, the river)?
- Relation to Surroundings: How well does the option’s scale and form complement and respond to the character of surrounding neighborhoods, buildings, parks, and historic districts/structures while being distinctive?
- Pedestrian and Cyclist Connectivity: How well does the option ensure safe and accessible connections on and off the bridge for people walking, biking or with disabilities?
Overall Look and Feel of the Bridge
- Bridge Overall Look: How well does the option’s overall form create a look of balance, unity, and flow from key viewpoints above, under, and away from the bridge?
- Bridge Form and Style: How well does the option acknowledge the historic and natural surroundings while presenting a seismically-resilient, modern design that sets the tone for future development throughout its 100-year design life?
- Flexible Design: How well does the option allow flexibility for engineering and architectural features in final design, as well as adaptability of the bridge for future user needs?
Cost and Construction Impacts to Users
- Total Project Cost: How well does the option minimize the Project’s total cost?
- Long Term Costs: How well does the option minimize long-term costs and support future needs after construction?
- Construction Impacts: How well does the option minimize impacts to the traveling public and surrounding property owners and tenants during construction?
Bridge Options Summary
Share Your Thoughts
We understand this is a lot of information. That’s why we need your input! Share what you like and why and help inform what the future Burnside Bridge should look like.
Survey Questions
Want to Know More?
Join us for a webinar with project team members to learn more and ask questions.
Wednesday, February 3, 5-6:00 p.m.
Next Steps
Thank you for your feedback! The online open house and survey comment period has closed. We will now use your input to inform the evaluation process. In addition to your expressed interests, we will work with partner agencies, community groups, and technical experts to evaluate these options and arrive at a recommended option. We’ll come back to the public in summer 2021 for feedback on the recommended bridge type before it gets approved for final design. During the final design phase, we’ll consider many other features and details of the bridge such as lighting, railings, operator towers, transportation features and connections, viewpoints, and more.
Stay Involved
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Resources
Visit the Earthquake Ready Burnside Bridge project website.
- Frequently Asked Questions
- Learn about the Draft Environmental Impact Statement and other alternatives studied
- Request a project briefing
- Check out project videos
Project Schedule
