Unique to any city in the U.S., light rail and heavy rail share the same tracks for portions of their journeys.  The joint running goes about two and one half miles, from near Tower City-Public Square downtown to just beyond the E. 55th Station.  Both systems use the common overhead wiring for their power source. 

Platforms here at East 55th are at two different heights for the to accommodate light rail and heavy rail.  The station, with its wooden platforms, hints at the age of the system. 

There's a major transit yard here for the entire RTA rail network.  In June of 2001, the time of this photo, there were some PCCs readily visible in storage.  It got one's juices really flowing.  By the time of my next visit to this area, more than four years later, they were gone to history.