FINALLY, AFTER four decades, a regional leader has proposed a long-term, earmarked funding formula for Metro that amounts to an adequate, sustainable and realistic means of assuring a healthy future for the transit system. Now it's time for leaders in the District and Maryland to reckon with Virginia Gov. Terry McAuliffe's blueprint and offer similarly serious plans of their own.

Limited by Virginia's constitution to one term and set to leave office next month, Mr. McAuliffe, a Democrat, didn't bother with the political gamesmanship that has so far characterized competing formulas for Metro offered by officials in the District and Maryland.

He did not pretend that raiding other transportation and transit projects for the next few years, on its own, was a sufficient strategy for rescuing Metro, as did Maryland Gov. Larry Hogan, a Republican. Nor did Mr. McAuliffe try to shift the burden of cost- ­sharing, as District officials have in proposing a regional sales tax that would reduce the city's contribution but nearly double Northern Virginia's.

Instead, Mr. McAuliffe urged a limited menu of new taxes on Northern Virginia, coupled with substantial cost-shifting from other regional transportation priorities, that would yield $150 million annually — the state's share of $500 million in additional annual spending on maintenance and safety that Metro says is the minimum required to regain long-term safety and reliability.

Unlike Mr. Hogan's proposed funding, Mr. McAuliffe's would be earmarked and permanent — and in that sense put Metro into the ranks of every other major American transit system. Unlike D.C. Mayor Muriel E. Bowser (D), whose constituents represent more than half of Metro's ridership, Mr. McAuliffe didn't try to airmail his obligations across the Potomac River. And unlike Virginia Republicans, Mr. McAuliffe doesn't deny a basic truth — that without substantial, predictable new funds, Metro faces a death spiral.

The tax hikes in Mr. McAuliffe's plan apply to hotel stays, home sales and wholesale gasoline in Northern Virginia, and they are modest. They would add $5 to a $500 hotel bill (mainly paid by business travelers). They would increase the grantor's tax paid by the seller of a $700,000 home by about $700, to $1,750. And they would probably add 30 cents, at most, to the cost of a 15-gallon fill-up at the gas station. The tax yield would be $65 million annually.

More painfully, perhaps, the plan would shift $85 million in annual spending to Metro from Northern Virginia roads, bridges and other transit projects — a major chunk of the state's annual regional transportation spending. That's a big hit, but it reflects Metro's critical importance.

Mr. McAuliffe's plan, in concert with similarly serious approaches from Maryland, the District and the federal government (whose employees make up 40 percent of Metro's rush-hour passengers), would meet the transit system's needs. It's not a stopgap, and it's not a ploy; it's an opening bid in what are likely to be protracted, complex negotiations. It recognizes that without a no-nonsense rescue plan, the consequences for Metro, and for the national capital region, are dire.