Metro planners trying to unclog the choked subway are proposing a bypass through the heart of the transit system: a new $6.3 billion subway line to run from Arlington County, under the Potomac River and through the center of the District to Robert F. Kennedy Memorial Stadium.

The suggested 22-mile leg, which is being called the new Blue Line, could include room for 11 new stations. Among them would be a stop in Georgetown -- at M Street NW and Wisconsin Avenue -- where the idea of a Metro station was shunned a generation ago but is now welcomed as a tonic for parking and traffic problems.

“Georgetown is the premier spot in Washington that does not have a Metro stop now. It should have had one and did not get one back in the ‘60s because of its own fault,” said D.C. Council Jack Evans (D- Ward 2), who represents Georgetown. “There was perceived and actual resistance [to Metro] in the neighborhood.” Evans called the plan a chance to correct Georgetown’s “tragic, major mistake.”

Business owners, residents and officials at Georgetown University echoed his words. “It would make life easier for many people,” said Ray Kukulski, president of the Georgetown Citizens Association.

The proposal would also give passengers on MARC, Virginia Railway Express and Amtrak a seamless trip between Union Station and Georgetown. And it would directly connect Prince George’s County with Reagan National Airport and other parts of Northern Virginia, while linking the Virginia suburbs with Georgetown.

The plan would also provide Metro managers new ways to route trains around trouble spots. That’s an ability long desired at Metro, a two-track railroad where one breakdown can -- and often does -- reverberate across an entire line.

“We’re a beautiful system and a terrific system, but we have many single failure points,” Metro General Manager Richard A. White said yesterday. “We need redundancy in the system.”

It’s unclear how the new Blue Line would be financed. Metro is facing a $5.2 billion shortfall during the next 25 years -- money needed for maintenance of the system as well as new rail cars, parking lots and buses to keep up with expected growth in ridership. Add the cost of a new Blue Line, and the deficit swells to $11.5 billion.

Like every other transit system in the country, Metro is hoping for a chunk of federal money when Congress approves the next transportation spending plan in 2003. The federal government has funded about 80 percent of Metro’s capital projects, with local jurisdictions paying the rest. The Bush administration has indicated it wants to reduce the federal share of such projects to 50 percent.

Transit officials gave no indication of how long it would take to build a new Blue Line but said the line would need to be operating by 2020 to meet ridership demands.

Metro directors listened to the proposal yesterday and asked for more details and information about how a new Blue Line would fit in the region’s plans for other transit improvements, such as a proposed Purple Line that would link Prince George’s and Montgomery counties.

Dan Tangherlini, transportation director for the District, said the region needs to consider a new Blue Line along with a range of other transit projects and set priorities as it seeks federal funds.

“We want to look at this very closely and explore it in the context of all transit developments,” said Tangherlini, who plans to meet with the governors of Maryland and Virginia at a Dec. 12 transit summit. “How does this relate to the Dulles Corridor, the Purple Line? We need to get our stories straight as a region what our priorities are for transit so we can have a strategy to pursue funding.”

The Blue Line proposal is part of a year-long study to analyze Metro’s capacity and identify changes needed to meet future ridership.

Metro is the fastest-growing subway system in the country, according to the American Public Transportation Association, and planners say it is quickly outgrowing its hub-and-spoke design.

Engineers expect that by 2020, the Orange Line won’t be able to absorb any more riders and that by 2025, the entire railroad will reach gridlock.

The solution, they say, is to untangle the Orange and Blue lines. Those two lines serve different parts of Northern Virginia and merge at Rosslyn, then share track through a tunnel under the Potomac River and across downtown Washington until they separate at the Stadium- Armory Station.

Because the two lines now share track, the capacity of each is cut by half. That is the main reason inbound Orange Line trains at, say, West Falls Church are standing-room-only during rush hour.

Because a certain distance must be maintained between trains, there’s a limit to the number of trains that can be sent down the Orange and Blue track each hour. Feeding trains onto the tracks is much like threading beads on a string; there comes a point when no more beads will fit. The Orange and Blue lines have nearly reached their limit of moving 26,000 passengers in one direction during one peak hour.

Plans to extend the Orange Line to Dulles, Tysons Corner and Loudoun County will only exacerbate crowding.

Transit engineers say they want to pull apart the Orange and Blue lines and run a new Blue Line through its own, new tunnel beneath the Key Bridge under the Potomac River. When it reaches the District, the new line would run north of the existing Orange Line. It would be separated from the Yellow and Green lines.

The plan also calls for creation of a rail link from East Falls Church to Rosslyn that would make it possible to run express trains on the Orange Line to downtown Washington.

The proposal would create room for more trains through the heart of the District, easing the congestion on the crowded Red Line. Just 19 percent of Metro’s 103-mile system is downtown, but that small chunk handles about 60 percent of 600,000 daily trips.