Metro proposes $26 million overhaul Metro's top managers are proposing a new rail tunnel under the center of the District, a second tunnel under the Potomac, and they estimate the transit agency will need $26 billion over the next three decades to pay for those and other improvements to an aging system that is falling behind the region's needs. The proposed new rail tunnels - one under 10th Street to Thomas Circle and another between Rosslyn and Georgetown and on to Thomas Circle - would be massive undertakings. The projects would require major financial commitments from local and federal governments and would take several years to plan and several more years to complete. Thinking long term for Metro Metro's strategic plan that will guide the transit agency's decisions over the next 10 years. It is not the first time Metro has talked about such new tunnels, but in making them a central piece of the transit agency's new strategic plan, Metro's top managers are seeking to focus public attention on what the agency says is a long-term threat to the region's economic growth. The 49-page strategic plan is to be presented Thursday morning to Metro's board of directors, which has yet to endorse the blueprint. "If we don't do something about what's coming at us in terms of the region's growth, we will have such a crowded system that it will create its own set of problems with regard to safety and infrastructure," Richard Sarles, Metro's general manager, said in an interview. Now is the time for the region - with Metro in the lead - to begin talking about projects that make the most sense for making long-term investments. The continuing population growth in the District and its suburbs, especially among young people who choose not to own cars, has made Metro's long-term capacity an existential issue for the transit system, one of the busiest in the nation. Along with the proposed tunnels, Metro says it must spend billions of dollars to upgrade the rail system's electrical grid to handle more eight-car trains and must add pedestrian corridors between transfer stations such as Metro Center and Gallery Place. Above ground, Metro needs to buy more buses, build more bus garages and create bus-only lanes on busy downtown streets. Dubbed "Momentum," and 18 months in the making, Metro's new strategic plan catalogues the system's needs and renews the long-standing argument for Metro to have a dedicated funding source, just as many big-city transit systems do. Metro's lack of capital investment in the past decade has been blamed on that lack of dedicated funding, and planners say that unless that changes, there is little hope of executing the ambitious strategic plan that will be formally unveiled Thursday. A new Metro line is being built in Northern Virginia, but it is being constructed for Metro by the Metropolitan Washington Airports Authority, with revenue from the Dulles Toll Road financing a significant part of the line's $5.6 billion cost. No such obvious source of financing exists for the new rail line and tunnels proposed in Metro's new strategic plan, and the plan does not specify how the agency would finance the rail expansion and other costly improvements.