It all started on a bus: NYC tribute to Rosa Parks
From "New Yorkers Take a Tribute Standing Up" in the New York Times.
From the article: It was meant to be a simple gesture to honor Rosa Parks, one of the giants of the civil rights movement, who died on Oct. 24 at age 92. The Metropolitan Transportation Authority asked riders on thousands of buses to remember Mrs. Parks by keeping the seat behind the driver empty.
I think that linking transit to its rich, but difficult, history wrt civil rights is another way to market transit within cities.