Park Street, a rare example where doors will open on both sides on the train
Red and Green Lines
North Station (Subway Station) is configured to have a cross-platform transfer between Southbound Orange and Green Line trains. Passengers switching from the Green Line can walk to the left to the Orange Line on the same platform and vice versa
Orange and Green Lines
The Green Line platform at Government Center is shaped like a triangle. Northbound trains use the "bottom" of the triangle, and Southbound trains use the "Left" side of the triangle. The "Right" side of the triangle-shaped platform is a former loop track for Southbound trains to reverse and head back north. It is only used during rare service changes and for storage. The Blue Line used to terminate here during some hours of the day and during weekends when Bowdoin was only open during certain times of a weekday
Green and Blue Lines
The Green Line platforms at Park Street are very interesting. Southbound trains share a platform and two tracks. Southbound B and C trains board on the left track, whereas D and E trains board on the right track. When trains arrive heading Northbound, they stop on a track with platforms on both sides. To the left of the Northbound track is a rarely used terminating track. If for some reason a D or E train uses the Park Street terminating track, they will be forced to board on the left track when heading back south
