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April 1, 2023

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Interstate 5 tunnel: To be or not to be?

Veterans of Columbia River Crossing, other projects explain drawbacks to idea

By , Columbian environment and transportation reporter

As predictable as traffic jams heading onto the Interstate 5 Bridge, state legislators are back in Olympia talking about Columbia River crossing options. And like other unchanging, interminable cycles, so returns talk of a tunnel solution to the river crossing problem.

Why do we not burrow beneath the Columbia River to solve our metropolitan-area traffic woes, rather than build a bridge above?

The tunnel option was explored, most recently, in the early days of the ill-fated Columbia River Crossing project.

All indications are it was not a long conversation.

“Tunnels are options that kind of get people from point A to point B,” said Kris Strickler, the highway division administrator at the Oregon Department of Transportation. Strickler was the Columbia River Crossing project’s deputy director.

“It just didn’t do as well as any of the options that were being looked at that were bridge-related.”

Columbia River Crossing project staff started working with the public, stakeholders and governments in October 2005 to articulate what, at a minimum, an alternative to the existing I-5 Bridge needed to do.

Planners wanted to know whether a given solution would:

• Increase vehicular capacity or decrease vehicular demand

• Improve transit performance

• Improve freight mobility

• Improve safety and decrease vulnerability to traffic incidents

• Improve bicycle and pedestrian mobility, or

• Reduce the seismic risk of the I-5 crossing.

In April 2006, staff looked at the 37 transit and crossing options they had gathered, and eliminated 22 of them. Eventually, they designed a 10-lane toll bridge with light rail and paths for bicycles and pedestrians. But in 2014, Republicans in the state Senate refused to fund Washington’s share of construction, and the project eventually was canceled.

Connecting the projects

The Columbia River Crossing project, Strickler said, was as much about connecting the areas at each end of the crossing as it was about getting across the river.

Even today, a new crossing would need to connect the freeway with state highways, downtown, the waterfront and elsewhere.

Meghan Hodges with the Washington State Department of Transportation, and Carley Francis, the agency’s Southwest Region administrator and then-spokeswoman for the crossing project, said the geometry of a tunnel would preclude that.

A tunnel would have to run well below the river’s 40-foot channel depth. To maintain a standard interstate highway grade, the tunnel would have to surface around Mill Plain Boulevard in Washington and south of Marine Drive in Oregon.

“By the time you get up to the roadway surface, there’s a good chance you’ve bypassed all of downtown,” Strickler said.

The new tunnel entrances would need whole new systems of connecting roads to state Highway 14, downtown Vancouver, Hayden Island and Marine Drive.

For example, Hodges said, state Highway 14 would need to be extended north to Mill Plain, which would require purchasing additional surrounding land. That would presumably include part of the Fort Vancouver National Site.

“These connections would also require significant out-of-direction travel for many users, including vehicles, transit, and bike/pedestrian travelers,” she wrote.

What’s next for a crossing?

Oregon and Washington lawmakers met for the first time to talk formally about an Interstate 5 Bridge replacement in December. The subject matter was nonspecific and process-oriented, but it at least got them talking, which is something considering the icy relationship between the two states when it comes to the bridge.

Beyond that meeting, the Legislature is still discussing transportation funding, which could include money for crossing-related projects.

Gov. Jay Inslee included $17.5 million in his proposed budget for an office for the I-5 Bridge replacement project. Late last month, Senate Transportation Committee Chair Steve Hobbs, D-Lake Stevens, released a 10-year infrastructure plan that included $3.17 billion for a replacement bridge.

Two other bills, in the House and Senate, would allow the Washington State Department of Transportation to designate qualified projects as being of “statewide significance.” Such projects would get a staff coordinator to help speed up planning, permitting and development.

Vancouver Democrats Sen. Annette Cleveland and Rep. Sharon Wylie are among the bills’ co-sponsors. Both bills were forwarded to their chambers’ rules committees for further consideration.

The House Transportation Committee did not pick up a bill to lay the groundwork toward a third bridge over the Columbia River in Clark County, proposed by Rep. Vicki Kraft, R-Vancouver, leaving that bill essentially dead.

On Wednesday, the Senate Transportation Committee passed a $15 billion transportation funding package that included an additional $450 million toward a new Interstate 5 bridge over the Columbia River. Sen. Annette Cleveland, a Vancouver Democrat who serves on the committee, characterized the money as a down payment toward design and planning, to go with future money from Oregon and the federal government once a solid plan gets going."

— Andy Matarrese

Hodges and Francis also noted that there would actually need to be two tunnels, north and south, to handle all of the demand.

Supplemental tunnel

So what about keeping the existing bridge and adding a tunnel for through traffic?

That idea was studied and dropped, “as it had marginal transportation benefits, considerably lower highway safety performance, very high capital cost, and higher community impacts,” according to the final crossing report.

Furthermore, planners said, much of the existing river traffic is local. Based on CRC studies, at least half of the freeway traffic would still end up on the existing bridge, which would still have the same performance and safety problems.

Again, the question isn’t necessarily whether a tunnel is technically feasible. Builders put a train tunnel under the English Channel and a 15-mile highway tunnel, the world’s longest, through a Norwegian mountain range. They could certainly burrow under the Columbia River.

But any future crossing project will likely be as much about connecting existing traffic patterns as it is about moving traffic across the river, Strickler said.

“That’s a keynote of that project, in past history, and I’m guessing it’ll be a keynote going forward as well.”

Ed Barnes, a longtime area labor leader and I-5 bridge replacement supporter, once served on a commission to address I-5 congestion, and also was a member of the state transportation commission.

At one time, he advocated for a supplemental tunnel as a means for some traffic to bypass snarls near the river, but then he started talking more to the engineers.

“I decided that it wasn’t a very good idea,” he said.

Beyond the problems of tying in other roadways and new frontage roads, a supplemental tunnel plan comes with potential earthquake hazards, he said.

“I would like to see it all go underground, but the expense of doing it — that’s a pretty big chunk of change,” he said.

He’s a tunnel fan, he added, but they’re probably not tenable for much of the region due to politics and the way the cities have grown.

About the only talk of a tunnel he sees anymore, he joked, are in letters to the editor.

“Tunnels are very good,” he said, “if you put them in the right place.”

Columbian environment and transportation reporter