Trains meet over Market St. in this view from the early 1980s.  The Budd cars were more than twenty years old at the time of this scene. 

The subway portion of the route was extended in the 1950s, and only six stations are outdoors west of center city.  For a mile or so from near 13th St. under downtown and to the west, the Market St. subway is four tracks wide.  The outer rails are used by light rail, SEPTA's "Subway Surface" routes.  There are two light rail stations along this portion where the Market-Frankford Line roars through as an express, of sorts.  Two other stations have platforms for each service.