|Type||Bus rapid transit, light rail, or heavy rail|
|Termini||Johns Hopkins Hospital
|Operator(s)||Maryland Transit Administration|
An independent 2002 commission on Baltimore-area transit made a number of suggestions for new lines and expansions of existing lines. The proposals used a unified branding scheme for the existing lines and the proposed new lines, identifying each line by a color, as the Washington Metro and many other transit agencies do. In the commission's report, the existing Baltimore Metro Subway was renamed the Green Line, and was to be extended northeast of its current terminus at Johns Hopkins Hospital, past Morgan State University and Good Samaritan Hospital in the northeastern part of the city, and ultimately on to White Marsh in Baltimore County.
The proposed extension of the Metro Subway was taken up by city and state officials as one of the two of the commission's proposals that would be actively pursued (the other being the Red Line). Although the report used the name "Green Line" to refer to the entire expanded Metro Subway, the term is currently being used to refer to the extension under consideration. However, in 2003 the Maryland Transit Administration began using green to identify the Metro Subway on maps, so it's possible that the term might someday refer to the entire line.
The current Green Line study focuses only on the section of the proposed line from Johns Hopkins Hospital to Good Samaritan Hospital. While an extension of the existing Metro Subway might seem like the most logical mode for this line, the expense of building several miles of underground heavy-rail rapid transit might make the project untenable. Therefore, the ongoing scoping process is also considering bus rapid transit, and light rail as a possibility for this corridor. 2012 is the earliest that revenue service would begin along this route.