The Green Line stop at Boston University West has on its signs a series of public art drawings. The drawings were made by a BU masters student, a local artist named Andy Bell. He happens to be a standup guy - I've been in communication with him about the art - and the signs are really neat:
Please note that those four images are NOT free use; the drawings contain the copyright of Mr. Bell, and I use them only under fair use, which is non-free.
This sign map, however, is free use:
The Boston Projection
1 day ago