Green Line Trolley at pulling into the station at Longwood Medical Area. The Green Line runs on city streets and partially underground through the downtown area. There are actually four Green Lines, designated by the letters B, C, D, and E. The fare is the same as for the subway Red, Orange, and Blue lines. If anyone noticed from a recent post, there is also a Silver Line. The Silver Line should have been a subway line, but for political and monetary reasons it is a Bus Line. The only bus line in the entire system that I know of that is designated by a color; the others usually are designated by numbers.
If your city has public transportation, how are the various lines designated?