GRANT COUNTY — Travel along I-90 between Ellensburg and North Bend through Snoqualmie Pass will be interesting for the next few years as the Washington State Department of Transportation prepares for the next phase of improvements to the eastbound section of the interstate and replaces the Vantage Bridge.

“It’s the primary east-west corridor for the state,” said Madison Scully, a design project engineer with WSDOT, during a Moses Lake City Council meeting on Tuesday. “It’s very important for the state.”

Scully said the work on I-90, which is slated to begin in earnest this year, will cover a five-mile segment of the eastbound interstate and involves the addition of a third lane of travel, the replacement of aging infrastructure and a number of safety improvements to the existing highway. The goal is to improve traffic capacity and flow, reduce the risk of rock slides, improve stormwater and snowmelt drainage and add wildlife bridges and tunnels, she said.

However, as the work proceeds, Scully said there will be significant lane closures, shoulder closures, traffic reroutes and detours. Blasting work has already started, prompting detours and temporary closures, she explained.

“There’s going to be backups and delays, and a slew of preservation and repair work of bridge decks,” she said. “Some will be more impactful than others.”

In addition, Scully said work is expected to begin this fall to completely replace the Vantage Bridge, which was first built in 1962 and last refurbished in 1982.

“It’s long overdue for repairs,” she said. “We do a lot of emergency repairs, and I think we were last out there two weeks ago.”

Replacing the bridge is expected to take three years, and is not expected to be finished until late 2026, Scully told council members. The work is complex because the entire bridge is made of steel, and so WSDOT crews are going to have to disassemble portions of the bridge while ensuring that it remains structurally sound for traffic use, Scully said. Most of that work will take place in 2024, while this year, WSDOT crews will likely focus on reinforcing the bridge in preparation for rebuilding it, she explained.

The concrete panels for the deck will be poured and allowed to set off site before being installed on the bridge, she explained.

“It will be a slightly different bridge deck once we’re finished,” Scully said.

As crews work on the Vantage Bridge, oversize and heavy loads will be prohibited, she said, with signs noting delays places as far east as Ritzville so drivers can take an appropriate detour, either through the Tri-Cities or Wenatchee.

“There will be some unique traffic configurations, and there will be very tight 11-foot lanes,” Scully said. “One direction of travel will be maintained at all times.”

However, Scully said even once the rebuilding project is finished, WSDOT crews will then repaint the bridge, a task that will take additional time and cause additional traffic delays. There was no way to combine the projects, she said, because the bridge would not be able to hold both construction crews and their equipment as well as paint crews and their equipment.

“Painting will take several years. We tried every conceivable way we could to get those projects combined, but it wasn’t feasible. There wasn’t a way to do it,” Scully said.

The I-90 repair work is the third phase in a lengthy series of upgrades to expand the interstate that began more than a decade ago to reduce avalanche risk to highway travel during the winter, Scully said, with no avalanche-related closures on the interstate since the completion of phase one. The wildlife bridges and tunnels not only help animals to cross the road safely, they also improve traffic safety by reducing the number of accidents on I-90, she added.

Charles H. Featherstone can be reached at [email protected].