Multnomah County hopes to start construction of a new, $895 million earthquake-proof Burnside Bridge within three years and is holding a public vote on what the replacement bridge should look like.

Planners expect to close the current Burnside Bridge for five years during construction, possibly beginning early in 2027. The county hopes to open the new bridge by the end of 2031.

Designers are choosing between two designs — a “cable stay” that evokes that Tilikum Crossing and a “tied arch” structure that resembles the Fremont Bridge. They’re asking residents to weigh in on which design best fits the surrounding urban landscape.

>> Take the county’s bridge design survey

The public vote won’t be determinative. A commission overseeing the bridge’s design will incorporate the vote into its own recommendations; the final decision belongs to the Multnomah County Board of Commissioners.

The bridge would have two lanes for auto traffic in each direction and an eastbound lane only for buses. Plans call for a 17-foot-wide bike and pedestrian path on each side of the bridge, the widest bike and pedestrian path of any downtown Portland span.

The county says a new bridge is essential because none of the existing spans in the city’s core could survive a huge Cascadia Subduction Zone earthquake, which geologists say will eventually strike the Northwest.

Local governments have pledged $300 million from Multnomah County’s vehicle registration fee, and Oregon lawmakers have allocated an additional $20 million. County planners are seeking other government funding, including grants from the federal infrastructure bill Congress passed in 2021.

Correction: Multnomah County says the bridge wouldn’t close until 2027, though some preliminary construction could begin in 2026.

-- Mike Rogoway covers Oregon technology and the state economy. Reach him at mrogoway@oregonian.com.

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