Columbia subject headings:
Local transit--United States--History--Case studies.
Urban transportation--Massachusetts--Boston--History.
Urban transportation--New York (State)--New York--History.
Urban transportation--Pennsylvania--Philadelphia--History.
Harvard subject headings:
Local transit--United States--History--Case studies.
Urban transportation--Massachusetts--Boston--History.
Urban transportation--New York (State)--New York--History.
Urban transportation--Northeastern States.
Urban transportation--Pennsylvania--Philadelphia--History.
Princeton subject headings:
Local transit--United States--History--Case studies.
Urban transportation--Massachusetts--Boston--History.
Urban transportation--New York (State)--New York--History.
Urban transportation--Pennsylvania--Philadelphia--History.