The Massachusetts Bay Transportation Authority would need to spend $7.3 billion to get its buses, trains, stations, and other assets in good working order, according to T officials.
The figure marks a substantial increase over a preliminary estimate of $6.7 billion issued in March. And officials said Monday it could grow even higher in the coming months as they refine their understanding of the scope of the problem.
The poor condition of the system’s trains and third rails is considered a significant driver of the MBTA’s breakdowns this past winter.
But Steve Poftak, a member of the fiscal and management control board that oversees the agency, said addressing the daunting backlog of repairs and upgrades is about more than preparing for snow and ice. It is the bedrock concern, he suggested, for an agency that needs to improve in all seasons.
“To me,” he said, “it’s the foundation of providing the MBTA service that riders deserve.”
A spokesman for Governor Charlie Baker, who has made overhauling the transit agency a centerpiece of his first year in office, praised the board for the thoroughness of its work but did not commit to more money for MBTA.
“The administration can now appropriately determine the best way forward in regards to funding while the financial health of the T is reformed,” Billy Pitman said.
The debate over fixing MBTA infrastructure has been a flashpoint in the discussion of what ails the nation’s fifth-largest public transit system.
Most observers agree the state has to do a better job of repairing and upgrading the T’s existing trains and switches. But Baker, who took office in January, argues that the T has been distracted from that core mission in recent decades by an unaffordable zeal for expansion.
Public transit advocates counter that the T has to continue expanding in order to foster economic growth in the region. The fundamental problem, they argue, is a historic lack of investment that has compounded the maintenance problems.
“This is the chickens coming home to roost,” said Rafael Mares, senior attorney with the Conservation Law Foundation.
The twin concerns, maintenance and expansion, were on full display Monday afternoon at a meeting of the fiscal control board, created to right the T after the agency’s winter crisis.
The panel reviewed the latest figures on the maintenance backlog. But it also took a first step toward hiring an outside consultant to examine how the estimated cost of a Green Line extension into Somerville and Medford exploded by $700 million to $1 billion.
Board members said getting to the bottom of the ballooning estimates, announced last week, is vital to restoring confidence in the T’s contracting procedures. And they suggested it would be politically difficult for the agency to proceed with the Green Line project without a review.
“I don’t think, at least for the public, that we can justify any decision going forward without giving them a full explanation of how we got here in the first place,” said board member Monica Tibbits-Nutt.
Board members suggested the review look at whether the T properly vetted a new contracting procedure, which some blame for the runaway costs. And the report, they said, should examine the agency’s broader management of the extension.
Joseph Aiello, chairman of the board, said the study should even contemplate bringing in an outside entity to oversee the Green Line expansion. “I’d like to get some radical thinking in there,” he said.
Stephanie Pollack, the state transportation secretary, said she would work up a proposal for the outside study and bring it back to the board for its review.
The T is projected to spend about $610 million on maintenance and upgrades in the fiscal year that began July 1, according to a report provided to the control board.
The report estimates that, at the current rate of spending, the agency would reduce its backlog to between $2 billion and $3 billion by 2040. Such spending would have to increase to an average of $765 million per year, in state and federal funds, to eliminate the backlog in 25 years, according to the presentation.
The true cost of getting the T’s equipment in a “state of good repair,” though, is almost certainly greater.
The spending estimates, officials said, have not been adjusted for inflation.
State Representative William M. Straus, a Mattapoisett Democrat who is co-chairman of the Legislature’s Joint Committee on Transportation, said the state will have to consider more spending eventually because “you will reach a point where if you’re not addressing ‘state of good repair,’ the consequences are even worse.”
“Then it does become a safety issue and a service issue,” he said. “And as we learned this winter, that’s just intolerable.”
In March, when the T released its $6.7 billion preliminary estimate for the maintenance backlog, officials made it clear that their review was incomplete.
Since then, the agency has fine-tuned its assessment of assets it had already logged in its database, whether train tracks or computer servers. It has also added tens of thousands of new assets, helping drive the boost in the estimated backlog to $7.3 billion.
David Scharfenberg can be reached at email@example.com. Follow him on Twitter @dscharfGlobe.