Sunlight At The Busiest Railroad Junction In The World. The interlocking at Tower 18 on the Chicago Transit Authority "L” at West Lake and North Wells Streets oversees the movement of Purple, Brown, Pink, Green, and Orange Line trains around the “loop”. The present building at this location was opened in 2010 as part of upgrades to track and signals. On the afternoon of August 9, 2016, CTA 5040 leads a train across Lake Street towards the Clark/Lake Station, showing Tower 18 on the northwest corner of the interlocking. This car was an early delivery of the 714-car "5000-series" Bombardier order (2009-2015). Becuase of the height of the buildings in the area, there are limited times during the day to catch sunlight on this scene.

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