Officials should have a more definite answer about the ballooning costs of the Green Line Extension by Thanksgiving, Gov. Charlie Baker said Thursday.
The cost estimate of the long-promised trolley extension from East Cambridge to Medford rose from roughly $2 billion last December to somewhere between $2.7 billion to $3 billion this spring — throwing the project into flux.
"There's something about this that's just not right," Baker told WGBH's Boston Public Radio. "I don't get what happened here."
The MBTA Fiscal and Management Control Board is pursuing analysis from an outside firm to study what happened to the project. Late last month, Control Board Chair Joseph Aiello said he wanted a "deep dive."
Baker said officials should have some answers over the next 30 days and a "complete answer" by Thanksgiving.
Calling himself a supporter of the project, Baker said he would not support it at a cost of $3 billion. "That's a 50 percent run-up in the total cost of this project," Baker said.