The Massachusetts Bay Transportation Authority uses a number of yards and facilities for maintenance and storage of its road and rail fleets.
Many of these facilities are former streetcar carhouses that were gradually converted to trackless trolley and bus use, although some like Southampton (built 2004) are of recent construction.
Of the former streetcar carhouses, only Arborway and Watertown were Green Line yards during part of the MBTA era.
Some provide ground power and other facilities; others are simply several yard tracks off the mainline.
Media related to MBTA yards at Wikimedia Commons