We should turn at the... say what?

Continuing the "say what" series of posts (began here and continued here), today's tantalizing tale tells of a time that occurred shortly after Lorena and I moved to Los Angeles and had to fill out the forms to transfer the payments for her Supplemental Security Income (SSI) disability from Salinas.  Our first attempt to do so landed us at the wrong building and one of the workers there told us where to go.  In our rush to get the task done, however, we forgot to get the directions for how to get there.  We soon remedied our lack of information at a nearby bus stop by requesting it from another lady waiting there.  I cannot recall most of what she told us mainly because I quickly concentrated on a single detail: that her directions involved us going north until we reached a green line.  Or rather, the green line, which seemed even more bizarre to me at the time, for I imagined my wife and I having to walk while searching for a literal green line (painted?) on the street (if you're reading this from the home page, you'll have to click below to read the rest...).
That's probably what we would have done, too, if my wife hadn't been more savvy to the ways of Los Angeles living and known that the lady was referring to the Metro Transit Authority's light rail green line: