MBTA General Manager Phil Eng announced the most extensive track improvement program the agency has ever undertaken Thursday morning — an overhaul that will involve dozens of service suspensions across all lines to lift the remaining 191 speed restrictions by the end of 2024.

“We have a new way of doing business,” Eng said — a way that he says will produce more efficient and timely work to return the system to normal operating speeds of 40 miles per hour.

Eng was confident that the MBTA has the funds and the management team to pull it off, citing their success with the recent two-week shutdown of a portion of the Red Line.

Chair of the Legislature’s Joint Transportation Committee William Strauss called the announcement a big day for the T, praising Eng and his new management team.

“I don't think there's any doubt that this kind of detailed plan ... would not have been something that was within the capability of the team a year ago,” he said.

There will be dozens of service suspensions ranging from four days to 21 days on all lines. The work will begin in December with a nine-day suspension of Green Line service service affecting routes into North Station from Kenmore, Heath and Babcock. Buses will provide alternate transit.