The proposal, considered unprecedented for T construction projects, will expand in both time and breadth the upgrades — and system shutdowns — that the Massachusetts Bay Transportation Authority had already scheduled. It will also require the T to spend $27.5 million more to make good on calls to more quickly tackle projects designed to improve service.

Facing intense pressure to speed repairs to its aging system, the MBTA intends to shut down core sections of the heavily traveled Red and Orange Lines, plus Green Line branches, throughout weekends in the fall to tackle the work, potentially hampering hundreds of thousands of riders.


For riders, that means closing a half-dozen stations in downtown Boston and beyond on any given weekend in October, most of November, and into December.

“To my knowledge, we haven’t done anything with this level of intensity [before],” the MBTA’s general manager, Steve Poftak, said of the planned repairs and weekend diversions, which officials will present Monday at a T board meeting.

The plan will close the eight Orange Line stations from Tufts Medical Center to Sullivan Square for six straight weekends in October and early November, affecting four out of every five Orange Line riders and up to 145,000 people each weekend, according to the T.

After that, the half-dozen Red Line stations from Broadway to Kendall Square — including South Station — will close for four weekends in late November and early December. The T estimates that project will affect three out of four Red Line users, or up to 155,000 over each Saturday and Sunday.

In both cases, the T will provide replacement buses, as it will on the Green Line, where it is planning closures over four weekends on the C or B branches, in addition to 14 weeks of previously planned outages along the D branch this fall.


T officials did not specify the time frame for shutdowns each weekend. But the projects come on top of weekend closures that officials had already planned throughout September elsewhere on the Orange Line and on a single weekend in early October on the Mattapan spur of the Red Line.

In short, outside of Thanksgiving weekend, part of the system will be shut down every weekend from Sept. 7 to the end of 2019 — remarkable, even for a transit authority that has regularly relied on less-traveled Saturdays and Sundays to complete projects. The closures are in addition to existing repairs being made on the Red Line since a June derailment.

T officials say the short-term pain of the wide-reaching shutdowns is the trade-off for more quickly addressing its long-neglected infrastructure.

“We clearly think it’s worth it,” Poftak said. “No one likes the inconvenience of diversions. But we need to make investments in the system, and this allows us to do it more effectively and more efficiently. We’ve heard loud and clear that people want us to accelerate the pace of improvements.”

The work will include adding signs and revamping the Park Street and Downtown Crossing stations, where work was originally expected to last until November 2020. In addition, officials will install 900 feet of new Red Line track near Downtown Crossing and Park Street, plus more than 2,200 feet of track at three Orange Line stations.

The onerous track work, which Poftak said wasn’t previously scheduled, requires the T to close stations well beyond Park Street and Downtown Crossing because heavy construction materials like tracks and ties can’t be hauled down the stations’ stairs. Workers have to take them into subway tunnels where they connect to the surface and then carry them along the tracks.


Thirty intersections and 7,000 feet of track will be upgraded on the Green Line’s above-ground B and C branches by late November. Jonathan Wiggs/Globe Staff/Globe Staff

Thirty intersections and 7,000 feet of track will also be upgraded on the Green Line’s above-ground B and C branches by late November, expanding on a project that was originally scheduled to run into mid-2020, officials said. Weekend shutdowns on the B branch are scheduled for Sept. 7-8, Nov. 2-3, and Nov. 23-24, while riders will be diverted on the C branch the weekend of Oct. 26-27.

State officials, including Governor Charlie Baker, have hinted at the possibility of more closings since late June, when the governor said he would seek a one-time, $50 million cash infusion for the MBTA, among other changes.

That proposal came just weeks after the derailment on the Red Line caused widespread delays and put the T’s financing under a microscope. Officials have yet to determine what caused the June 11 derailment, they said, though repairs there are expected to continue into October.

Poftak framed the accelerated work as an initial phase of the plan to more aggressively tackle repairs throughout the system. He said officials are still building a schedule for 2020, when larger projects will be on deck, and he indicated shutdowns could at some point not be limited to weekends.


“Weekday closures is something we’re examining for future years,” Poftak said.

Joseph Aiello, who chairs the Fiscal and Management Control Board, which oversees the T, and to which officials will present the plan, said he supports the efforts to speed repairs. But he wants to see how the additional weekend closings play out this year before committing to more in the future.

“I’m hopeful that this is very well thought out and that there are no unintended consequences,” he said. “No matter where we try to open up additional windows to allow the track and signal gang to do their work, we know we’re disrupting somebody. We are being as careful as we possibly can in designing these.”

In scheduling the work, officials tried to be surgical, Poftak said. They tracked major events — from concerts at Fenway Park and TD Garden to conferences in the Seaport — and attempted not to squeeze them with station closings.

Regular service is planned the weekend after Thanksgiving, which is on Thursday, Nov. 28.

“You really want to keep the downtown as transit-accessible as possible that weekend, for both mobility purposes but also for important retail and customer and business reasons,” said Richard A. Dimino, president of the business group A Better City, which has pushed the T to more quickly invest in improvements.

“That the T is actually getting creative, to get the work done and get it done quickly, is something we have to be open-minded to,” he said.


Boston Mayor Martin J. Walsh, who has criticized the T since the Red Line derailment, was optimistic, calling the T’s plan “a first step towards better service.”

“Boston has been calling for a more reliable, more accessible MBTA,” his statement said. “It is imperative that this work happen efficiently and with as little disruption as possible.”

Matt Stout can be reached at matt.stout@globe.com. Follow him on Twitter @MattPStout.