An El train on the Elevated train system crossing Wells Street Bridge, Chicago, Illinois, United States of America, North America

An El train on the Elevated train system crossing Wells Street Bridge, Chicago, Illinois, United States of America, North America

Skyline and Dubai Metro, Modern Elevated Metro system, opened in 2010, Dubai, United Arab Emirates, Middle East

An El train on the Elevated train system, Chicago, Illinois, United States of America, North America

View of intricate rail and road network crossing, Minato City, Tokyo, Honshu, Japan

A vibrant view of Tokyo skyline featuring train tracks weaving through modern skyscrapers in a busy district, Tokyo, Honshu, Japan

An El train on the Elevated train system crossing Wells Street Bridge, Chicago, Illinois, United States of America, North America

El train on the elevated train system, The Loop, Chicago, Illinois, United States of America, North America

El train on the elevated train system, The Loop, Chicago, Illinois, United States of America, North America

Under the El, the elevated train system in The Loop, Chicago, Illinois, United States of America, North America

An El train on the elevated train system crossing Wells Street Bridge, Chicago, Illinois, United States of America, North America

Supporting system, Wuppertal Floating Tram suspended monorail, Wuppertal, Bergisches Land region, North Rhine-Westphalia, Germany, Europe