While city residents waited almost 2 1/2 years for Sunday’s scheduled reopening of the repaired West Seattle Bridge, they’ve also spent nearly $6 million to plan a replacement structure that’s not supposed to be needed until 2060.

The city payments flowed to giant engineering firm HNTB and subcontractors, who conferred with local transportation managers, evaluated possible alignments and performed partial bridge engineering. HNTB concluded that the best place for a new road bridge is directly on or overlapping the existing bridge’s footprint.

The seven-lane high-rise, built in 1984, has been closed since March 23, 2020, when multiple shear cracks, discovered seven years earlier, accelerated 2 feet in two weeks. Since then, drivers have detoured as far as 6 miles, often wasting 30 to 60 minutes.

The future-bridge strategy was announced long ago by the Seattle Department of Transportation, with consent by Mayor Jenny Durkan and the City Council, to provide fallback options in case of another emergency.

A council ordinance in September 2020, to approve $70 million debt for the $175 million Reconnect West Seattle program, mentioned “analysis and design of bridge replacement options” as an expected expense. High-bridge stabilization and permanent repairs account for $78 million of the program.

SDOT program director Heather Marx told council members a month earlier that as an agency of planners and engineers, “Having to keep moving forward, when we don’t know what the end of the road looks like, is uncomfortable for us, as well as I’m sure it is for you.”

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An initial agreement with HNTB was signed in October 2020. New-bridge planning continued after Durkan’s decision in November 2020 to repair the bridge rather than replace it immediately, after a separate report by Seattle’s consulting bridge-maintenance engineers that said repairs had a 95% chance of lasting until 2060, and after a technical advisory panel of bridge experts predicted repairs would succeed.

It’s a subjective question: Did the city use tax money wisely to plan a project intended for decades in advance — money that could be spent to fill potholes, add sidewalks or refurbish aging drawbridge parts?

“I don’t apologize and I don’t feel bad about making these contingency plans,” Marx said. She emphasizes SDOT still devoted $35 million for repaving, signals, pedestrian safety and traffic-calming projects meeting local needs, including in Highland Park and South Park neighborhoods flooded by detour traffic.

Kevin Broveleit, a real estate agent who formed the West Seattle Bridge Now coalition to prod SDOT for a rapid bridge reopening, said new-bridge planning should have ceased in fall 2020, once contractors stabilized the cracked bridge.

“Any money spent on designing a future bridge was wasted money because we have no idea what we we’ll need in 40 years, especially considering light rail is at hand,” Broveleit said.

City payments to HNTB wrapped up in June 2022, totaling $5.8 million, the city says.

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The seven-lane West Seattle Bridge is scheduled to reopen Sunday, with no fanfare at an unannounced hour, to avoid the risk that drivers will cluster on the hillside vying to cross first.

The city scaled back what could have been a $50 million to $150 million bill for a full replacement-bridge design, announced in spring 2020 shortly after the emergency closure, when the old structure was considered at risk of collapse. Marx’s team then held spending below an $8.9 million cap in their April 2021 second-phase contract with HNTB by canceling studies of traffic demand, financing sources and seismic conditions.

HNTB declined an interview request and referred questions to SDOT. Its other recent projects include the Highway 99 tunnel, loaded with safety features.

Work products

The company issued a 184-page report in December. It says the best position for a new bridge is identical to or overlapping the existing alignment. Locations north, south or underground were deemed too cumbersome or expensive. The report described four workable bridge types. At that point, planning bills reached $2.88 million.

Continuing through mid-2022, HNTB completed 30% of a design for a steel arch type that’s relatively quick to build, Marx said.

Former Mayor Greg Nickels, who co-chaired the bridge’s citizen advisory panel, recalls that two years ago, while members differed about repair versus replacement, they supported SDOT’s future-bridge study as a good compromise.

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“Do the planning for the replacement, but recognize it was so far in the future that the transportation needs might change” was his theme. Nickels said it’s a good insurance policy, in case repairs don’t last.

Local history offers reason to doubt that early planning delivers early results. Sound Transit 3 light rail is mired in a seventh year of process in Ballard and West Seattle. In the ’00s, outreach and preliminary engineering to replace the Alaskan Way Viaduct burned through eight years, 75 route permutations, and $300 million before Gov. Chris Gregoire abandoned the process, choosing a deep-bored Highway 99 tunnel. The fear of a prolonged permit process was one reason Durkan chose repair over replacement.

The HNTB report itself cautions: “It could take 14 to 20 years to deliver a project,” including eight years for planning, funding and design, then six to eight years of construction. Or longer if other projects, such as a new lower Spokane Street drawbridge, are built concurrently.

“It is never a bad idea to be prepared for the worst to happen,” Marx said.

Asked about runaway process, she called planning costs in West Seattle, for the busiest city-owned corridor, “a drop in the bucket” compared to other megaprojects. About 100,000 vehicles and nearly 20,000 transit riders per day crossed it before the crack crisis.

Almost replaced

Even before signing a contract, HNTB almost persuaded the city to choose immediate replacement.

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Ted Zoli, the firm’s renowned national bridge engineer, presented a concept in October 2020 for twin network arches — whose crisscrossing steel cables secure the decks — that would rest upon delta-shaped support frames. Bridge spans would be manufactured off-site then lifted onto existing columns over the Duwamish River, he said. Based on a successful bridge replacement at Lake Champlain, Vermont, he said the project here could be accomplished in 3½ years.

City staff leaned toward replacement. They cited a fresh cost-benefit analysis, led by SDOT’s longtime bridge advisers at the WSP engineering firm, to argue that old-bridge maintenance costs, plus the price to build anew someday, would cancel the dollars saved by a repair.

Ex-SDOT chief Sam Zimbabwe said last week the limited study was worthwhile, to provide rough cost comparisons and discard less-desirable options.

“At some point that will need to happen, and the corridor’s not going to get any less complex to build in.” He added: “Until the repair was executed, there was still some level of uncertainty.”

Price of advice

City Councilmember Alex Pedersen, chair of the Transportation & Public Utilities Committee, called the nearly $6 million investment beneficial, “especially for precise location identification that enables Sound Transit to properly locate their separate light-rail bridge.”

The citizen panel didn’t delve into planning expenses, said Nickels and co-chair Paulina López, executive director of the Duwamish River Community Coalition. López recalls a sense that SDOT was obligated, at least by some of the public, to study a future bridge.

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One vision HNTB’s report didn’t explore was a shared crossing, that combines motor vehicles with transit trains.

Instead, the study anticipates Sound Transit will build a train-only crossing south of the road bridge, and that conflicts must be avoided. But keeping a future road bridge within SDOT’s existing airspace may pose another challenge, HNTB says: slicing through the meridian of the 1984 bridge, so half the old deck can stay aloft and provide road lanes during a multi-stage replacement job.

Some elements of the study have a long “shelf life,” especially knowing where a new road bridge is buildable, said City Councilmember Lisa Herbold of West Seattle.

Reconnect West Seattle is expected to be completed below its $175 million overall budget, which encompasses high-bridge and low-bridge strengthening, new pavement, traffic signals, and transit subsidies.

Whatever money is left over, Pedersen said, should be dedicated to fixing other city bridges.