The
Fairmount Line or
Dorchester Branch is a line of the
MBTA Commuter Rail system in
Boston, Massachusetts,
USA. Except for a short portion in
Milton, it lies entirely within Boston, progressing in a southwesterly trajectory, passing through the neighborhoods of
Dorchester,
Mattapan and
Hyde Park. It sees service roughly every half hour during
rush hours and approximately every hour or less at other times, though with no night service. Weekend service began on November 29, 2014. Most trains reverse direction at the south end at
Readville, but a few continue onto the
Franklin Line.