Item B: I-5 Willamette River Bridge - ODOT Update

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ODOT is designing the new bridges wide enough to eventually carry up to six-lanes of traffic (three-lanes in each direction) to meet the projected long-term traffic needs. The new bridges will be striped to carry two lanes in each direction, matching the existing alignment of I-5. Any future widening of I-5 would require a full environmental review. How was the deck arch design chosen? The decision to build a deck-arch bridge for the I-5 crossing over the Willamette River follows nearly two years of discussion and relationship-building with residents and local government officials in Eugene and Springfield, along with full consideration of design opportunities and constraints. ODOT’s goal is to strike a balance between design characteristics of highways and bridges and an affordable budget that responsibly uses transportation funding. Since these discussions began, the costs of bridge materials such as asphalt, concrete and steel have increased beyond projections. As a result, a preliminary cost estimate for a through-arch bridge recommended in a community survey is more than $20 million over the project budget. This means ODOT simply cannot find a fiscally responsible way to build a through-arch bridge. After revisiting bridge choices that fit the project budget, and considering community input, ODOT chose an option with arches under the deck. The deck-arch bridge, with its graceful curves and attractive profile, strikes a balance between a distinctive design and economic reality. 2