Built at the dawn of the automobile age, the viaduct was probably the first limited access highway as it is elevated as it circumnavigates Grand Central Terminal.  The space under the viaduct was originally used as a trolley barn.  By 1938 it had become a tourist information center within that space for the 1939 New York World's Fair.  During World War II, the space was used by United Service Organizations, and after the war, became an outpost of the New York Convention and Visitors Bureau.  It is now a restaurant.