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The Portland City Council on Wednesday made a small but significant decision regarding the Earthquake Ready Burnside Bridge project.

Though Multnomah County is the project owner, the city of Portland has road authority, so configuration of the lanes is its decision, Sharon Daleo, major projects engineer for the Portland Bureau of Transportation, stated on Wednesday. Accordingly, the council voted 4-0 (Commissioner Mingus Mapps was absent) in favor of the Refined Preferred Alternative version of the project.

However, the council added two amendments: one to ensure that the pedestrian/bicyclist connection from the bridge to the Eastbank Esplanade would be an ADA-accessible ramp, and another to establish width minimums of the two bridge areas reserved for pedestrians and bicyclists (one for each direction).

鈥淢y preference would have been not to be doing this amendment,鈥� Commissioner Jo Ann Hardesty said, adding that she had hoped the pedestrian/bicyclist ramp would have been included in the Refined Preferred Alternative.

Initially, to reduce cost, Multnomah County recommended that the bridge be built with stairs and an elevator. However, most of the public testimony given during Wednesday鈥檚 council meeting expressed serious doubt about reliability 鈥� specifically that an elevator might not be functional in an emergency.

鈥淲e want to make sure that during an emergency that the bridge is accessible for any and all people that need it,鈥� Hardesty said. 鈥淭hat鈥檚 why a ramp is so vital to us as supporting this bridge.鈥�

The Portland Bureau of Transportation has studied four concepts for the ramp. Daleo indicated that 鈥淐oncept 4,鈥� an asymmetrical helix structure, would potentially have the least amount of impact and cost 鈥� if the spiraled section were to move north of the bridge.

A key constraint in the ramp design is a highly liquifiable patch of soil. Daleo said that during a major earthquake a lateral shift is expected to occur in this area, so any structure built would require an extensive soil amendment or large columns for support.

In March, a Community Task Force endorsed a plan to narrow the Burnside Bridge replacement so that the cost would be limited to $895 million. This included reducing the number of vehicle lanes and the width of the pedestrian/bicyclist space from 20 feet to somewhere between 14 feet and 17 feet.

Under the current proposal, the new Burnside Bridge would have four vehicle lanes (one of which would be for transit vehicles only) instead of five. It would have a bascule movable span and a girder structure for the west approach.

The City Council鈥檚 amendment approved Wednesday stated that each of the bicyclist/pedestrian areas (one on each side of the bridge) should be no narrower than 17 feet.

The Earthquake Ready Burnside Bridge project is now set to return to the environmental review phase. A final record of decision is expected to be made by the Federal Highway Administration in December 2022 or January 2023, according to Multnomah County.