Van Buren Street Tunnel

Between 1892 and 1906, Chicago had three cable car tunnels under the Chicago River. Two were built for pedestrian and horse traffic and later converted, the third was built specially for cable-cars. After cable service ended they would be used by electric streetcars. By 1900, Chicago had a cable-based transit system that carried 80 million passengers a year, but all cable routes leaving downtown to the North or West had to cross the navigable Chicago River. Heavy shipping traffic required movable bridges, which cable lines couldn't cross. Two existing public tunnels were converted for cable use, and a third was built as a private venture. In 1906, all Chicago cable lines were converted to electricity and the tunnels were closed. All would reopen for streetcar service, but with the change to electricity streetcars could cross bridges and the tunnels were less important. One ended regular service in 1924, one was closed in 1939, and one remained in regular service until 1952. In 2010 all approaches had been covered but two tunnels still existed. These tunnels should not be confused with a network of small freight tunnels under the downtown area.

Tunnel data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).