FOR THOSE who should care most about Metro's long-term financial health, including its 700,000-odd daily subway riders, two recent developments provide modest grounds for optimism. One is the indictments of Rep. Tom DeLay in Texas and the resulting removal of the congressman from his post as House majority leader. Mr. DeLay may well have planned to obstruct congressional efforts to promote a reliable stream of local funding for the Washington area's mass-transit system. Another is the effort by regional jurisdictions, albeit still inchoate, to devise a strategy to take advantage of a mouthwatering financial carrot: a 10-year, $1.5 billion federal fund for Metro.

The $1.5 billion carrot is the brainchild of Rep. Thomas M. Davis III (R-Va.), who would make that sum available if area localities took several steps, including, crucially, guaranteeing Metro a steady, earmarked source of local funding. His bill to accomplish that has decent prospects for passage, although it may not be helped by the demands of hurricane relief and reconstruction on federal dollars.

If Mr. Davis's bill does become law, it might not be for another year or more. In the meantime, though, local leaders and transportation officials have begun thinking about how to fulfill the promise of the bill's $1.5 billion incentive -- in other words, what local funds to earmark for Metro. They are very far from substantive progress -- Maryland officials are still trying to figure out what might count as earmarked funding -- and are likely to remain so until and unless Mr. Davis's bill becomes law. But the very fact that meetings and discussions are underway is an encouraging sign that the region's elected representatives grasp how important it is that they succeed.

The problem is stark: Metro, the nation's only major mass-transit system that lacks a dedicated revenue stream, is a beggar; it relies annually and precariously on the good will of area localities to pay its bills. At the same time it faces steadily growing ridership, especially if gasoline prices continue to soar, coupled with daunting infrastructure problems. Without a long-term financial plan that takes all that into account, the system will be doomed to increasingly frequent delays, breakdowns, accidents and worse.

A politically viable deal to secure Metro's future -- one that might involve new taxes in some or most area jurisdictions -- may not be achievable before elections this year and next in Virginia and Maryland. Still, now is the time for local officials to debate, formulate and begin to advocate funding strategies.