PORTLAND, Ore. (KOIN) — The recommended replacement for the Burnside Bridge would be earthquake ready, uses the fewest support columns and is the least expensive of the 4 alternatives, the Multnomah County task force announced Tuesday.
The new long span bridge would replace the current Burnside Bridge in the same spot and alignment, officials said. Using fewer columns in liquefiable soils gives it the least risk of movement in an earthquake and avoids some “geotechnical hazard zones” near the Willamette River.
The exact type of bridge will be decided in 2021 — either a tied-arch superstructure like the Fremont Bridge or a cable-stayed bridge like Tilikum Crossing. The final design of the bridge will take 3 years.
The cost for the proposed bridge is $825 million and would take more than 4 years to build beginning in 2024.
The task force also recommended not building a temporary bridge during construction. The additional $90 million for the temporary bridge would only carry a fraction of the traffic and add 2 years to the construction timeline.
In August, public comment will begin on this recommendation. A vote on the preferred plan is expected on October 2.
Another public comment period will begin in 2021 for the federal requirements about the environmental impact. The Federal Highway Administration will need to approve this project before it begins.