Metro is trying to find long-term solutions for alleviating congestion in its 37-year-old rail system, and the agency’s planning staff argues that adding longer cars or building various streetcar, light-rail and bus rapid transit systems that have been proposed for the region isn’t likely to be sufficient to solve the problem.

More stations and tunnels are needed, Metro officials argue. Not to reach new and different parts of the region, but to take the pressure off its most heavily used and crowded lines.

Even though the Silver Line isn’t expected to open until early next year, Metro’s biggest choke point is already in Rosslyn, where rush-hour commuters in both directions regularly see filled-to-the-brim train cars pass them by. Metro began raising the possibility of a new underground tunnel between Rosslyn and Georgetown nearly a year ago, part of $26 billion in overall improvements the agency has proposed.

Now Metro’s planners have begun suggesting that the region add 10 new stations and create four “super stations” by adding capacity and connections around the two Farragut Square stations, Union Station, the Capitol South station and the Pentagon station.

The 10 new stations have not been named. But going clockwise from Rosslyn, they look something like Rosslyn II, Georgetown University, Georgetown, West End, Thomas Circle, Mount Vernon Triangle, Capitol Hill North, Navy Yard II, Waterfront II and Potomac Park.

The actual locations have not been decided, but the idea is to have them built by 2040. (The plan does not include a proposed station at Potomac Yard because the push for that station is coming from the City of Alexandria.) The $26 billion figure probably will change as the planning staff refines plans and costs. The public and the Metro board are likely to weigh in on the proposals by July.

The proposed stations and connections, chosen over three other concepts, reflect the need to expand capacity in the system’s core, said Shyam Kannan, Metro’s chief planner. “The inner lining, where we share tracks for two lines, worked for 40 years but becomes a problem going forward given the demands of the system,” he said.

Setting aside the costs, there are some obvious regional benefits to Metro’s proposal.

First: Rosslyn. By adding a second Rosslyn station, Metro relieves its biggest choke point and clears the way for an efficient connection between the region’s two major economic hubs: downtown Washington and Tysons Corner. “We would need to get that done first. Once you’ve solved the Rosslyn problem, it opens up a lot of options to make the rest work,” Kannan said.

Second: Union Station. With Blue and Silver lines connecting to Union Station — the busiest Metro stop and the region’s largest rail hub — passengers at a “super station” there could get off a train or bus and get to Dulles International or Reagan National airports without transferring.

Adding new lines at Union Station also would alleviate much of the congestion on the Red Line, the rail system’s oldest and busiest line. Having Union Station dumping so many riders onto the Red Line so they can transfer elsewhere, Kannan said, doesn’t make sense. “Having all that traffic simply shunt off onto the Red Line is simply not a sustainable solution long-term,” he said.

Third: Farragut. A tunnel with Orange and Silver line service that people could reach by walking underground from the Farragut North and Farragut West stations would further ease pressure on the Blue and Red lines.

No matter how crowded trains are, or how many disruptions there are on the Red Line or elsewhere, $26 billion or thereabouts is a big ask for a region where the vast majority of residents still do not use public transit to get to work.

A new report from George Mason University’s Center for Regional Analysis says that one in seven of the region’s commuters use public transit. That’s about 14 percent, a rate that’s been pretty steady since 1990. Public transit use is much higher in the District, Arlington County and Alexandria, at 32.7 percent, on average. For Montgomery, Prince George’s and Fairfax counties, the rate is 13.7 percent, and in the farther-out suburbs, including parts of West Virginia, the rate of commuting by public transit is 3.9 percent.

Many of the jurisdictions George Mason studied are not covered by or supportive of Metro — meaning they are not members of the compact that contributes funding to the agency. But of the 14 sites where Metro proposes adding new stations or expanding existing stations, 12 are in the District and two are in Arlington; there are none in other areas.

With the increasing value of real estate near Metro stations, that’s potentially a major influx of long-term tax revenue for the District, financed by all the jurisdictions.

Metro’s planning staff has begun to combat this argument ahead of time. For one, Kannan points out that Maryland has six entry points to Metro’s inner core, while Virginia has only two. He also has data showing who uses stations that are in greatest need of relief, and it turns out that many of them are from the Maryland or Virginia suburbs.

Many of the core stations are utilized by riders from outside the District. Pink indicates riders from Maryland suburbs included in the Metro compact. Yellow indicates riders from Virginia suburbs included in the compact. Gray indicates riders from farther out jurisdictions. (Courtesy of Metro)

The argument goes that although the two Maryland jurisdictions — Montgomery and Prince George’s — would not be getting any new stations within their borders, their residents have a lot to gain by achieving relief in the core. Of Farragut North riders, 61 percent live in Maryland, for instance. More than half of Farragut West riders come from Virginia.

(Courtesy of Metro)

All of this is in the early stages of study. Metro plans to analyze how the new stations and connections would affect ridership, crowding and transfers between lines. As Washington City Paper pointed out recently, there may be too much overlap with the District’s streetcar system, now under construction.

And as the Greater Greater Washington blog pointed out, there are multiple operating scenarios for the new loop should it be built.

But the increasing demand for walkable, transit-oriented neighborhoods helps Metro’s argument that the core of the system needs to be expanded for the rest of it to retain its efficiency and value.