PORTLAND — The new Sellwood Bridge opens to traffic next week, nearly — but not quite — ending what has been a long and bumpy road to replace the crumbling span.
The project is already slightly over budget, and it’s not finished yet. The eastside approach remains unfinished because of a temporary connection to the old bridge, used as a detour during construction. And the west end still lacks a direct ramp to southbound Macadam Avenue. The remaining construction should be finished by November.
Construction will snarl at least a couple more commutes, too. The old bridge closes at 7 p.m. Thursday while crews adjust lanes to match traffic patterns on the new overpass, which opens at 6 a.m. Tuesday.
In the meantime, Multnomah County is hosting a sendoff for the old bridge Thursday night and a ribbon cutting on the new bridge Saturday.
The $307.5 million project is now looking like it will cost $319 million when all is said and done. The project already burned through $12 million in a budgeted contingency fund, as well as $10 million added to the budget after better-than-expected bond sales.
The cushion from the bond sale will cover unexpected costs up to $317.5 million. Beyond that, the city and the county will each cover half the cost overruns, with the county portion coming from vehicle registration fees.
The bridge project began in earnest a decade ago, when the county detected cracks in the existing two-lane span. It instituted a weight limit on the existing bridge as a temporary measure while working on financing for a replacement.
Multnomah County thought the bridge would be paid for with state funds, a contribution from the City of Portland and vehicle registration fees from itself and Clackamas County. The state’s most populous county instituted its $19 a year fee, but Clackamas County voters in 2011 rejected their $5 a year contribution, which had been budgeted to raise $22 million.
A last-minute, $17.7 million grant from the federal government offset the resulting shortfall even as construction preparations had already begun.
The span sits in the middle of a bowl formed by an ancient landslide. The project included efforts to stabilize the soil against future slides, but workers found upon digging into the hillside that the soil was even looser than expected, forcing a redesign.
Problems drilling into the riverbed pushed costs higher. The county sparred with a subcontractor, California-based Malcolm Drilling Co., which sued for reimbursement of higher-than-expected costs. The county settled in December for $792,150.
However, the project is so far well within its forecast in one area — traffic closures.
Construction has closed the bridge for a total of 15 days in the four years of work. Another five days in the next week would bring the total to about 20. County officials agreed at the outset that the bridge wouldn’t be closed for more than 30 days, to prevent downriver traffic problems and to avoid hurting Sellwood businesses.
