In March 2002, the Baltimore Region Rail System Plan Advisory Committee, an independent commission appointed by Transportation Secretary John D. Porcari, developed suggestions for new lines and expansions of existing lines as part of a long-term regional rail system plan for the Baltimore area.

In the committee's report, the existing Baltimore Metro SubwayLink 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.

As the existing Metro SubwayLink is currently marked in green on the Baltimore Regional Transit Map,[3] it's possible that the term might someday refer to the entire line.

[4] While an extension of the existing Metro SubwayLink 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.

[5] North to south, from Johns Hopkins Hospital station: Selection of a "locally preferred alternative" from the various transit options under consideration was originally scheduled for "Spring 2009 - Winter 2009."