Metro executives have devised a strategy to raise the $1.5 billion they say is urgently needed to maintain and repair the rail and bus system, but the proposal requires heavy investment by the counties and cities Metro serves.

Transit officials said the strategy, which requires approval by local governments by mid-September, is central to keeping the Metro system running.

"This is not a program that represents all that we could do for the region, or all that we should do," said Chris Zimmerman, who represents Arlington on the Metro board of directors. "It is simply what we absolutely have to do to avert disaster. This is just the first step. If we don't get this done, the region's in a whole lot of trouble."

Metro managers say they need to raise $1.5 billion between now and 2010 to purchase 120 rail cars and 185 buses, expand rail maintenance facilities, upgrade rail power systems and build a bus garage, among other things. That will enable Metro to maintain the current level of service while absorbing projected ridership growth over the next six years, they said. It does not allow for expansion of rail or bus service.

The plan would also improve security by allowing Metro to install more chemical and biological sensors throughout the subway system, equip bus garages and other Metro facilities with intrusion alarms, and add cameras to buses.

In addition to the local money, Metro's strategy assumes the federal government will provide $290 million -- an assumption that might not be accurate. Congress has not acted on a pending transportation bill.

For most of this year, Metro Chief Executive Richard A. White has lamented that his agency has pressing financial needs that are going unmet. He has warned that without a serious infusion of cash, Metro is poised to tumble into a "death spiral" similar to the deterioration experienced by the New York City subway during the 1970s.

Metro is the only major transit system in the country without a dedicated source of funding through a portion of a local tax set aside for transit.

Instead, it must beg for money each year from local governments, which leaves it vulnerable to the political climate and makes long-term planning difficult.

"At best, our annual budget process is a juggling act," said T. Dana Kaufman, who represents Fairfax County on the Metro board.

Since March, Metro officials have been negotiating with local jurisdictions to come up with a funding plan for capital needs. "We've been bringing in armies of people on a weekly basis -- all the lawyers, all the financial people from all the governments," White said. "There have been legions of people working on this. We really feel this is one massive, massive step forward."

The strategy represents a shift in the way Metro pays for capital items such as new rail cars and buses. Until now, the transit system waited until it had all the money needed for a purchase before it proceeded.

Under the new plan, called the Metro Matters strategy, the transit agency will operate on a pay-as-you go basis, so that it can proceed with a contract as long as it has the immediate payment at hand.

White said yesterday he was hopeful that local governments would agree to fund the Metro Matters strategy.

The plan does nothing to address another budget problem looming before the transit system. Metro is facing a $42 million shortfall in its next operating budget, which will begin next July.

The operating budget pays for wages and benefits, fuel and other short-term costs associated with running trains and buses. Operating costs are paid through a combination of passenger fares, subsidies from governments and revenue from advertising and other sources.

For the past two years, Metro has resolved its operating deficits by raising passenger fares. Board members have said they are reluctant to consider raising fares for a third straight year.

Health insurance, wages, workmen's compensation and fuel are among the factors driving up Metro's costs, budget analysts said. Since 2000, Metro has doubled the amount of money it spends on health care for its 9,000 employees.

"The pressures we're facing are similar to the pressures every household is facing," said Gordon Linton, who represents Montgomery County on the board.

Metro executives told the board yesterday that if fares are not raised, subsidies from local governments would have to rise by 10.4 percent to erase the projected shortfall of $42 million. That would be a significant jump. Historically, local subsidies have increased by about 4.5 percent annually.

Metro chief Richard White says a new payment system needs support.