Rehabilitate the Sellwood Bridge

We’re happy to welcome Jim Howell to the rolls of Portland Transport contributors with this perspective on a potentially less costly way to deal with the Sellwood Bridge.

The apparent assumption that the Sellwood Bridge must be replaced and that it will take ten to twenty years to do it is misguided. This historic 1925 structure is currently suffering from lack of maintenance and lack of respect. Both problems can be remedied.

We’re happy to welcome Jim Howell to the rolls of Portland Transport contributors with this perspective on a potentially less costly way to deal with the Sellwood Bridge.

The apparent assumption that the Sellwood Bridge must be replaced and that it will take ten to twenty years to do it is misguided. This historic 1925 structure is currently suffering from lack of maintenance and lack of respect. Both problems can be remedied.

The existing bridge’s useful life can be extended another eighty years by completely rehabilitated it for vehicles, bikes and pedestrians.

If county officials and the public can live with a complete closure during construction and are willing to pay for it with bonds repayable with tolls and/or local and state gas tax revenues, not federal funds, it can be done within five years.

The protracted process and huge expense of a replacement span mandated by federal prerequisites, not common sense or local and state requirements, can be avoided if no federal money is involved.

The results of an analysis of the structural condition of the bridge, performed by David Evans and Associates, answered the question about what can be done to extend the life of the bridge for up to fifteen years. However the detailed results of the study did not identify any fatal flaw that would preclude the possibility of rehabilitating the bridge for a much longer useful life at a cost much less than what a replacement span would cost.

The four main steel truss spans, which cross the open water of the river, are in fine shape in terms of strength, although they are suffering from deteriorating paint and a leaking deck. The components that are slowly failing, and that need immediate attention, are the deck support system (“floor beams” and “stringers”) and the approach spans.

In addition to the repairs described in the Evans report, the deteriorated west approach structure, bridge deck and railings should be replaced, and the bridge repainted. Also, the roadway should be widened and a new deck for pedestrians and bicycles could be built underneath the main deck of the bridge.

A below-deck bicycle/pedestrian facility supported by the lower chords of the trusses would be protected from rain and vehicle spray and could provide an easy connection to the Springwater Trail. At the west-end, the new approach structure could be built to provide for bus stops with ramp and stair access to the bike and pedestrian level as well as to a train stop on the proposed Lake Oswego Streetcar Line.

The impact of the Sellwood Bridge closure on commuters can be greatly reduced if a temporary bus ferry system is established to shuttle buses, bikes and pedestrians across the river from the foot of Spokane Street during rehabilitation.

Of course TriMet would have to agree to provide a frequent east-west bus route between Clackamas County and Washington County in the Johnson Creek Blvd./Tacoma Street/Taylor’s Ferry Road corridor. This route would provide convenient connections to many existing bus routes and major transit hubs like Clackamas Town Center and Washington Square.

Although tolls aren’t essential to the concept of rehabilitating the bridge, this project could provide local experience in modern tolling techniques before they are considered for larger highway projects in the metro area. Since 60% of the trips across the bridge originate outside of Multnomah County, helping pay for refurbishing the bridge with a user fee (toll) seems fair.

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