The project underwent four evolutions in shape and route, at a budgeted design cost of $10.9 million to date, before an additional $27 million in bridge construction begins.

Share story

Compared to other Seattle transportation projects, it should be easy to design a pedestrian and bike bridge over Interstate 5 at the Northgate light-rail station now under construction.

Nobody’s home will be demolished, or afflicted by noise. Neighbors will be a mile closer to transit. The bridge would serve an estimated 3,000 daily users, including North Seattle College students, and double the territory where people walk or bike to the trains. Everybody likes it.

Yet five years after City Council approval, the bridge is still not fully designed.

The project has undergone four evolutions in shape and route, at a budgeted design cost of $10.9 million to date. That’s before starting construction that will cost an additional $27 million.

The design phase slipped 18 months due to “approved changes” and “unforeseen conditions,” says an online report card for levy-funded Move Seattle projects.

Pressure is mounting for the Seattle Department of Transportation (SDOT) to meet its promised mid-2020 opening, before trains reach Northgate in 2021. An earlier city fact sheet in 2015 showed completion aimed for this year.

Cost estimates hovered awhile near $60 million for a more dramatic tubular-shaped bridge the city preferred, where people would walk through a hexagonal prism of white steel spokes.

That’s been discarded in favor of concrete spans and an arched overhead truss for a total cost of $37.9 million.

Who pays?

Funding sources for the $37.9 million Northgate Station bridge over Interstate 5:

• Move Seattle property-tax levy, $15 million

• State grants, $10 million

• Other city funding, $7.6 million

(mainly real estate tax and street-user fees)

• Sound Transit, $4 million

• Federal grants, $1.3 million.

Source: Seattle Department of Transportation, 2018-23 Capital Improvement Plan

The college and city remained at odds over where the bridge would land on the west side. For years, college leaders objected to diagonal paths that would block a trail and divide a grass field that might also be needed someday for college buildings.

Finally, lawmakers intervened and demanded high-level talks this winter. Cooperation improved, and leaders this month agreed on a direct east-west path that ends at a city street.

“We’re really happy. The community and ourselves are really looking forward to this,” said college President Warren Brown. “We want it done right. We want it done on time and on budget.”

But the project isn’t out of the woods.

Traffic Lab is a Seattle Times project that digs into the region’s thorny transportation issues, spotlights promising approaches to easing gridlock, and helps readers find the best ways to get around. It is funded with the help of community sponsors Alaska Airlines, CenturyLink, Kemper Development Co., NHL Seattle, PEMCO Mutual Insurance Company, Sabey Corp., Seattle Children’s hospital and Ste. Michelle Wine Estates. Seattle Times editors and reporters operate independently of our funders and maintain editorial control over Traffic Lab content.

Learn more about Traffic Lab » | Follow us on Twitter »

“I’m concerned that the cost estimate given to us is $37.5 million, but that the city still hasn’t costed-out the west approach,” said state Rep. Gerald Pollet, D-Seattle, whose district includes Northgate. “I have to be a healthy skeptic about what the cost estimate is.”

Negotiations continue over environmental permits, wetlands, easements and, above all, security standards, Brown said. The city agreed to cut some deciduous trees at the college’s behest, so bridge walkers can see farther and be less vulnerable to crime.

The college also wants Sound Transit or SDOT to assume security liability and patrol the bridge.

Long history

For a generation, Northgate neighbors discussed a pedestrian bridge to close the gouge caused by freeway construction in the 1960s. Mayor Greg Nickels in 2007 proposed it in his bicycle master plan. The project became more real in 2008 when voters approved the Sound Transit 2 sales-tax increase, which funds rail to the University District, Roosevelt and Northgate stations.

Most Read Local Stories

Unlimited Digital Access. $1 for 4 weeks.

Four years later, the City Council voted to proceed. A King County structural engineer estimated costs at $17 million for a steel-truss bridge or $19 million for a cable-stayed bridge.

But the city embraced a more ambitious idea — a tube formed of X-shaped cross members, designed by Seattle-based LMN Architects, award-winning creator of UW Station at Husky Stadium.

“I remember being at the meeting, having the design unveiled, and being as excited as hundreds of constituents about it,” Pollet recalled.

There was a catch.

The hexagonal tube required steel frame below the walkway. How could that happen, yet still clear the freeway by at least 17½ feet, while descending from the high train platform to the college grounds? The answer was to make the spans longer, and go diagonally to the southwest instead of a shorter east-west line across I-5.

The city promoted that landmark shape in spring 2014, but put the job on hold during 2016, after learning it would cost $60 million. Then-SDOT director Scott Kubly, who arrived in mid-2014, looked for a less-expensive option.

“Rather than try to find more money, we decided we would live within our means,” he recalled.

The SDOT in early 2017 switched to VIA Architecture, which pared the project to $37.9 million. The former 2,100-foot-long diagonal crossing is now a straight 1,600 feet, and the walkway width shrank from 20 feet to 16 feet.

“Our goal is to serve the client and get this project buildable again,” said Eric Birkhauser, VIA’s project manager.

Shapes and layouts for the Northgate Station/Interstate 5 bridge changed four times, turning simpler after cost predictions hit $60 million and North Seattle College insisted on a straighter path. The city scrapped a 2015 plan for a honeycomb of white steel tubes. (SDOT)
Shapes and layouts for the Northgate Station/Interstate 5 bridge changed four times, turning simpler after cost predictions hit $60 million and North Seattle College insisted on a straighter path. The city scrapped a 2015 plan for a honeycomb of white steel tubes. (SDOT)

His team integrated parts of LMN’s vision, including its white-gray color, wood handrails, LED lights and some of the tubular structure.

“The previous design was a strong form that created an icon for the corridor. How can it still be very emblematic of the region?” he said.

VIA’s answer was a gentle peak in the truss, to resemble Mount Rainier, he said.

Funding also required a struggle.

Agreements in 2012 called for the state to chip in $10 million, Sound Transit $5 million and SDOT $5 million, before costs rose. The city competed for a $15 million federal grant but missed the cut.

Then-Mayor Ed Murray turned the gap into a selling point for his Move Seattle levy, by putting a $15 million Northgate bridge earmark into the campaign-promise map provided to voters.

As the tubular concept faded, the college issued a counterproposal in May 2017, to straighten the bridge and touch ground on North 100th Street. But midyear, the city published another diagonal path, and a steep slope of 8.3 percent on the west end.

Legislators’ letter

Three state legislators from the area became so worried about delays they wrote a letter demanding a meeting with city and college officials. That occurred Dec. 20.

The letter by Pollet, Rep. Javier Valdez and Sen. David Frockt, all Democrats, also questioned whether the city knows the costs. They assert the city unfairly blamed the college for process delays, and didn’t keep legislators abreast of design and budget changes.

City staff say they’ve worked with the college to change alignments, and the budget should hold at $37.9 million, barring last-minute changes. Staff say design costs are within a normal range, less than one-third the project total.

“SDOT is currently on track to open the Northgate Pedestrian Bridge in 2020 before the opening of the new Sound Transit light rail station, which opens in 2021,” said spokeswoman Mafara Hobson.

To stay on course, the plan needs a yes vote from North Seattle’s and the state’s college trustees this spring. SDOT also must complete a study of affected lands, under federal environmental law to protect parks and nature preserves. That couldn’t be done sooner, because the college and city first had to agree on the route, Hobson said.

Meanwhile, Sound Transit says it would pay just $4.3 million for bridge construction. The agency contends it already spent $700,000 to make its station platforms compatible to the bridge. It’s also contributing another $5 million to walk-bike paths east of I-5.

Pollet insists Sound Transit should contribute the full $5 million to bridge building, and cover any further overruns, since the purpose is to boost light-rail ridership. The bridge will save Sound Transit money, he said, because light-rail riders who live immediately west of I-5 won’t have to useexpensive park-and-ride stalls at the station.

Policymakers should decide early who will control and fund huge transit-related projects, he said. “Handing off to SDOT is clearly a problem, and SDOT’s mismanagement has continued to compound it,” Pollet said.

“I’ve wanted this bridge built for more than six years, and dang it, I want to see it built. That’s the big picture,” he added.

Valdez said he became involved because the college asked for help, and the face-to-face talks made him optimistic. “My hope is that the project gets completed on time and on budget. It’s critical and essential,” he said.

City Councilmember Mike O’Brien, chairman of the Sustainability & Transporation Committee, didn’t respond to interview requests, while Councilmember Kshama Sawant’s staff said she declines comment. Rob Johnson, the third council committee member, was unavailable due to a family emergency.

President Brown says he’s excited about the bridge’s benefits, especially the direct links it will provide to the University of Washington and Seattle Central College via light rail.

Yet he also calls the five-year process an example of “lessons learned.”

“I certainly wish we would have started more detailed negotiations years ago. But we are where we are. The city thinks they can make the timeline.”