Boston is home to the old subway in the county, the Green Line, which will be extended by 4.7 miles from Lechmere Station to Somerville and Medford. This opened at the end of the 19th century and was built to allow ordinary street cars to operate below ground which is dramatically different than subways of today.
The busiest Green Line stop is Park Street station, which is the intersection of the Green, Orange and Red Lines in the heart of Downtown Crossing.
Banker & Tradesman recently reported that the “U.S. Transportation Secretary Anthony Foxx yesterday joined Gov. Deval Patrick and other Bay State officials to formally announce a $996 million federal grant to extend Massachusetts Bay Transportation Authority (MBTA) Green Line light rail service from East Cambridge to Somerville and Medford…The Federal Transit Authority announced its intention to provide nearly $1 billion for the $2.3 billion project in December. State funds will cover the remaining cost.”
You can read the full article on B&T.