Metro and TriMet are taking concrete steps this summer to determine if it’s feasible to build a tunnel underneath downtown Portland and the Willamette River to speed up light rail trains and provide an alternative river crossing to the aging Steel Bridge.

The regional government quietly posted a new website this week dedicated to the MAX tunnel project, which would put MAX trains underground from roughly the Lloyd Center to Goose Hollow in Southwest Portland. The website includes a public survey asking for comments on the tunnel concept.

Right now, Metro officials stress they are just trying to study the idea, likening it to a plan for planning.

“The MAX Tunnel study is a feasibility exercise to determine what it would take to do the entire environmental (EIS) planning process and all the engineering and design necessary to build a project like this,” Eryn Kehe, a Metro spokeswoman, said in an email. “By this September when we finish this study, we should have a cost estimate for the planning/design process and an idea of how long it would take.”

But the feasibility study would set the groundwork if, or when, the region decides to dive into the tunnel talk more seriously in coming years.

The overall tunnel project would likely cost at least $1 billion. A preliminary concept described a “twin-bore east-west transit tunnel” that would emerge on the west side on Jefferson Street near S.W. 16th Avenue and on the eastside near N.E. Holladay Street at 16th Drive.

Potential underground stations include the Lloyd Center, Rose Quarter, Union Station, Pioneer Square, Portland State University and Goose Hollow. The underground stations would be able to accommodate four-car trains, twice as long as the standard MAX vehicle.

It may be one way to address the Steel Bridge, which every MAX train currently crosses, and its transit logjam. The Steel Bridge opened in 1912. TriMet last fall indicated that it was eyeing its light rail future beyond the Steel Bridge, which is owned by Union Pacific Railroad, and carries five bus lines, five MAX lines and dozens of freight and Amtrak passenger trains every day.

During the busiest part of the day, Metro says 40 light rail trains cross the bridge, or one every 90 seconds. “As the region grows and the demand for light rail increases, the region will need at least 64 MAX trains through downtown every hour, more than one train each minute. Our current system can’t support that change,” the project website says.

Kehe said initial estimates indicated a tunnel would cut travel times by 15 minutes between the Goose Hollow and Lloyd Center stations. Today, a train ride between those two stops can take 23 minutes, according to TriMet’s transit planner.

“That’s a lot of time especially if you’re commuting two times a day,” she said.

The tunnel discussion is increasingly percolating in transit circles. This week, TriMet General Manager Doug Kelsey brought up the idea again during discussion about potentially closing three MAX stations downtown as a way to carve a few minutes off a commute.

“We’re going to need to speed up and yes, I believe eventually go underground,” Kelsey said Wednesday.

Metro’s blueprint for regional transportation projects of big importance in the coming decades already includes reference to replacing the Steel Bridge and a potential tunnel. The plan refers to the need to address “the transit bottleneck at the Steel Bridge and Rose Quarter," and cites 2016 figures at $700 million. The project is pegged to a 2028 to 2040 timetable.

The regional government is also leading the planning effort for a 2020 transportation package, a ballot initiative that is expected to total in the billions of dollars and features the proposed light rail extension to Bridgeport Village as a key project. TriMet leaders have previously said they would like a plan to either replace the Steel Bridge or otherwise address the transit bottleneck with a tunnel or other options like shifting MAX lines to other bridges, to be included on the 2020 ballot measure.

Metro plans an open house July 22 at its 600 N.E. Grand Ave. offices at 4:30 p.m. to hear public comments on the tunnel concept.

-- Andrew Theen

atheen@oregonian.com

503-294-4026

@andrewtheen

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