The MBTA wants to spend $3.5 billion to increase the capacity and ridership on the Green Line with new, longer trolley cars.
At a meeting of the Fiscal Management and Control Board Monday, officials said they wanted to use longer trolley cars to increase use and growth of the Green Line.
The subway line itself will present a bit of an infrastructure challenge in getting new cars, said officials.
"There certainly are some -- how would you say, peculiarities? -- to the Green Line itself. The Green Line has a number of challenges that is certainly different than anything we experience on the Orange Line and the Red Line," said Jeff Gonneville, deputy general manager of the MBTA.
The T estimates it could take more than a decade to add new Green Line cars, fix tight turns, and improve two dozen Green Line stations.
Officials have secured less than one-third of the funding needed for the project.