Columbia subject headings:
Automobiles--Illinois--Chicago--History--20th century.
Local transit--Illinois--Chicago--History--20th century.
Traffic engineering--Illinois--Chicago--History--20th century.
Urban transportation policy--Illinois--Chicago--History--20th century.
Harvard subject headings:
Automobiles--Illinois--Chicago--History--20th century.
Local transit--Illinois--Chicago.
Traffic engineering--Illinois--Chicago--History--20th century.
Urban transportation policy--Illinois--Chicago--History--20th century.
Princeton subject headings:
Automobiles--Illinois--Chicago--History--20th century.
Local transit--Illinois--Chicago--History--20th century.
Traffic engineering--Illinois--Chicago--History--20th century.
Urban transportation policy--Illinois--Chicago--History--20th century.