Consultants working on the Massachusetts Bay Transportation Authority's Green Line extension say the original design for a two-mile path along the project would cost about $100 million.
The Boston Globe reports MBTA officials estimated that the community walkway would cost about $40 million in 2014, but that figure likely didn't include several features that the transit authority is looking to cut.
A new proposal for a path that would cost $20 million was introduced at a community meeting held Wednesday at Somerville High School.
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MBTA general manager Frank DePaola told the crowd that officials are doing their best to deliver a project that is both affordable and accepted by the public.
The MBTA has said it will only continue with the extension project if costs dropped considerably.