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The New Bridge and Interchange

Steel Deck Arch

A detour bridge is carrying traffic until the new Sellwood Bridge opens in 2015. Learn more about the detour bridge.

At their January 27, 2011 meeting, the Multnomah Board of County Commissioners agreed with the recommendation of the Community Advisory Committee (CAC) and Public Stakeholder Committee (PSC) and approved a steel deck arch bridge type for the replacement Sellwood Bridge.

Conceptual renderings

Conceptual rendering of the new Sellwood Bridge, looking east

View of the new Sellwood Bridge, looking east

Conceptual rendering of the new Sellwood Bridge, looking west

View of the new Sellwood Bridge, looking west

Conceptual rendering of structural lighting on the new Sellwood Bridge

Structural lighting

Conceptual rendering of bench, railing and lanes on the new Sellwood Bridge

Plan view of bench, railing and lanes on
the new Sellwood Bridge

Conceptual rendering of bench and railing on the new Sellwood Bridge

Bench and railing on
the new Sellwood Bridge

OR 43 Interchange Detail

OR 43 Interchange Detail

The new Sellwood Bridge will be a deck arch structure, with three arches supporting the deck of the main river spans. (What is a steel deck arch?)

Why a Steel Deck Arch?

In their consensus recommendation for a Steel Deck Arch bridge type, the CAC noted the following:

  • Arched form fits the natural setting
  • Appropriate to neighborhood scale
  • Open steel structure echoes character of existing bridge
  • Top-ranked form in public on-line survey
  • Adds to city's unique bridge collection
  • Can be built within the established budget
  • Has high technical performance
  • Sustainable – components are made of recycled steel
  • Provides employment opportunities for local firms to build

The Locally Preferred Alternative

The Locally Preferred Alternative, selected in 2009, determined that the new Sellwood Bridge would:

  • Be built in its current alignment and widened 15 feet to the south to allow for continuous traffic flow during construction
  • Be 64 feet at a cross-section of its narrowest point: two 12-foot travel lanes, two 12-foot shared use sidewalks, and two 6.5-foot bike lanes/emergency shoulders
  • Include a grade-separated and signalized interchange at the OR 43 (SW Macadam Avenue) intersection on the west end
  • Include a pedestrian-activated signal at the intersection of SE Tacoma Street and SE 6th Avenue on the east end
  • Be consistent with the Tacoma Main Street Plan
  • Restore bus and truck traffic; and accommodate possible future streetcar

Extensive public outreach occurred during the selection of the Locally Preferred Alternative to ensure that the public was involved in the process in a meaningful way.

After the planning process was complete, including the necessary approvals from state and federal agencies, Multnomah County and its partners sought to reduce the project costs and shrink the overall footprint, particularly at the west end connection with Highway 43. Planners succeeded in trimming the project back and reducing environmental impacts while maintaining multimodal functionality, safety and traffic performance.

Refinements made to the Locally Preferred Alternative, approved by the Multnomah County Board of Commissioners in 2011, include:

  • Compressed interchange design that saves money and shifts project away from hillside
  • Reduction in size of the west end rock (cut by 50% - 40 feet high rather than 80 feet high)
  • Alignment revision to accommodate future streetcar at a safer location
  • Bicycle/pedestrian spiral ramps replaced with switchback ramps
  • Less impact to Riverview Cemetery

This graphic shows the current configuration of the Sellwood Bridge project:

Current Locally Preferred Alternative
(Click to download PDF, 399 kb)