Metro tests new 7000 series subway cars last year in Shady Grove, Md. (Bill O'Leary/The Washington Post)

AFTER YEARS of pushing by the Washington region’s bipartisan representatives on Capitol Hill, Congress, stunned by the death and destruction in Metro’s Red Line accident in 2009, finally agreed to a long-term financial aid package to help lift the transit system from penury. Under the terms of the deal agreed to six years ago, the federal government would furnish Metro with $150 million annually for 10 years, a $1.5 billion shot in the arm to modernize and maintain the system, to be matched each year by an identical amount from Metro’s three main funding partners: the District, Maryland and Virginia.

Until now that pact has held, through the travails of sequestration, venomous partisanship and decaying congressional consensus on so much else. But in recent days there have been worrying signs it is fraying. Even in the face of fresh worries about Metro’s safety and ageing infrastructure, Congress seems set to break its promise. That would be a terrible blow to the federal workforce and to the region’s transportation and security infrastructure.

On Tuesday a subcommittee of the House Appropriations Committee approved a transportation funding bill that would cut in half the federal government’s annual appropriation to Metro. In an act of supreme legislative chutzpah, the panel also said federal transportation officials must certify that Metro spends its money on projects that make safety the highest priority.

So even as Congress would slash $75 million in annual funding whose purpose is to modernize equipment and safety systems on the 40-year-old subway, lawmakers wag a finger and remind Metro that it had better improve safety.

It’s worth reminding Congress that Metro, whose weekday ridership consists heavily of the federal workforce, remains the only city rail system in the nation that lacks a permanent dedicated funding source. That glaring deficiency led it to defer critical maintenance and system improvements even as ridership steadily grew in the decade preceding the Red Line crash, Metro’s deadliest mishap.

The absence of such funding contributed to, among other things, a postponement in replacing outmoded rail cars, which should have been underway in the last decade. It was only after Congress sealed the 10-year deal, with its promise of steady annual funding, that Metro was able to go ahead with a long-term rail car replacement program. Unless Congress restores the $75 million in annual funding for Metro, that improvement, and others, will face further delays.

Alarmed at that prospect, the region’s bipartisan congressional delegation issued a statement warning that “anything less” than the full federal commitment of $150 million annually would imperil not only critical safety improvements but also, conceivably, the dollar-for-dollar match from the District, Maryland and Virginia.

That may be a particular danger in Maryland, where the new Republican governor, Larry Hogan, has made it clear that he regards mass transit as a secondary priority to building highways and roads. Why give Mr. Hogan a pretext to revisit his state’s own commitment to such a vital component of the capital region?

Read more about this topic:

The Post’s View: Another disaster for Metro