Clackamas River bridge design narrowed to five options
Public input is wanted on five concepts for replacing the Clackamas River trolley bridge that collapsed in 2014.
Federal grants largely funded these $1.453 million studies of the feasibility of extending the Trolley Trail south of Portland Avenue for pedestrian and bicycle traffic only. The actual construction of the bridge would cost between $4.9 million and $10.9 million, depending on the style of the bridge chosen.
Project leaders say that input from the community will be taken into consideration, along with the bridge design, cost and permitting requirements.
Bridge structure options being considered include:
• A single-span, steel truss bridge is being considered because the design looks like the previous trolley bridge. The estimated $6.6 million bridge would be easier to permit because no columns would be in the river.
• A precast, prestressed concrete bridge is a common type of bridge structure in Oregon. The total project cost of $4.9 million is the lowest among the alternatives, but the bridge would be harder to permit because of the columns in the river.
• A steel truss, another common bridge type in Oregon, could be built for an estimated $5 million. This design also is more difficult to permit because of the columns in the river.
• A single-span, steel arch bridge's aesthetic qualities match the beloved bridge between Oregon City and West Linn, but the estimated $10.9 million cost is the highest being considered. This bridge would be easier to permit, given no columns in the river.
• A three-span bridge estimated to be $5.5 million also would require columns in the river and look like many other Oregon bridges.
You count on us to stay informed and we depend on you to fund our efforts. Quality local journalism takes time and money. Please support us to protect the future of community journalism.