Commuters ride a train at McPherson Square Metro station. (Ricky Carioti/The Washington Post)

IN PROPOSING a $500 million annual bailout for Metro in equal four-way contributions from Maryland, the District, Virginia and the federal government, Maryland Gov. Larry Hogan could be playing political chicken, or have come to a sudden appreciation of Metro’s dire need — but it doesn’t much matter.

What does matter is that Mr. Hogan, a Republican not enamored of mass transit, has put an offer on the table. The other three players ignore it at their own peril — and at peril to the region’s economic vitality.

Mr. Hogan's blueprint — $125 million annually from Annapolis over four years, on the condition that it is matched by Metro's three other funding partners, for an annual total of $500 million — is an abrupt about-face and a welcome one. Just two weeks ago, at a meeting with District Mayor Muriel Bowser, Virginia Gov. Terry McAuliffe, both Democrats, and other officials, the Maryland governor stunned the room by ruling out any increase from Annapolis in current funding levels for Metro.

Given the network’s huge projected capital shortfalls — critically needed funding for new subway cars and a host of other major projects designed to revive a subway system in long-term decline — Mr. Hogan’s adamant, not-another-dime stance was a promise of indefinite misery for commuters.

The spin from Mr. Hogan’s camp is that his initial line in the sand was just a feint in what he anticipates will be prolonged negotiations. Whatever the strategy or motivation, his reversal now provides the prospect of a lifeline to a flailing system whose projected 10-year capital funding deficit is $7.5 billion.

Granted, Mr. Hogan's suggestion would meet only a part of Metro's minimum need. If Virginia, the District and the feds all kicked in for four years, as he urged, the combined new capital infusion would amount to just $2 billion. Nor is Mr. Hogan putting forward any dedicated funding from an earmarked tax of the sort that is the lifeblood of virtually every major American subway system. Rather, having ruled out any new taxes when he ran for governor in 2014, he offers to find new dollars for Metro simply by shifting funds around in Maryland's transportation trust fund. If some other state project may be shortchanged, Mr. Hogan isn't saying.

Already, officials elsewhere in the region are grumbling that the governor’s gambit is a bluff. Specifically, there are grave doubts that the federal government, whose current $150 million annual capital spending for Metro expires after next year, can be relied on to renew that plus the additional $125 million on which Mr. Hogan’s offer depends.

But what better way to put the feds on the spot than for the District and Virginia to chime and chip in? And by dropping other heavy-lift preconditions for additional Metro funding—such as further streamlining of operations, or governance and labor reforms — Mr. Hogan has simplified matters by clarifying that the system’s immediate crisis is mainly about funding.