French Prairie Bridge Task Force Identifies Two Bridge Types for In-Depth Study

December 17, 2018 — On December 5, the French Prairie Bridge Task Force identified two bridge types — suspension bridge (pictured above) and cable stay bridge — for further evaluation as the City continues to develop a proposal for a bike/pedestrian/emergency vehicle crossing over the Willamette River.

Provided the task force’s recommendations are endorsed by City Council in January, the French Prairie Bridge project team may begin a more detailed assessment of the two bridges, including impacts, renderings and cost estimates.

This in-depth evaluation is informing the selection of a preferred bridge type, scheduled for consideration by the Wilsonville City Council and Clackamas Board of County Commissioners in April.

The Task Force reviewed five possible bridge types, including input provided by the Technical Advisory Committee and the general public. A steel truss bridge was eliminated for aesthetic considerations, a tied arch bridge was eliminated because of potential costs and environmental impacts.  A steel girder bridge was preferred by some task force members as the least expensive option, but the majority of task force members favored a more aesthetically-pleasing solution that delivered fewer impacts.

Beyond visual appeal, rationale cited by the Task Force for its selections included appeal to visitors, cost considerations and a desire to have as little impact as possible on the Willamette River, marina operations and Boone’s Ferry Park.

The French Prairie Bridge would fill a critical gap in the region’s multi-modal transportation infrastructure, connecting the Portland metro area to the Willamette Valley Scenic Bikeway and narrowing a 30-mile gap that separates local Willamette River crossings for cyclists and pedestrians.

For more information, visit frenchprairiebridgeproject.org or contact Zach Weigel, Capital Projects Engineering Manager, 503-570-1565; weigel@ci.wilsonville.or.us.