The smaller passage was for streetcars. Camden Interstate was the company. Served Huntington, Ashland, Ironton and points in between.
My guess is that it was built for pedestrian passage.
That's an odd one. Makes me wonder if that smaller passage on the right was originally for power lines or something else.
The locals call this Pike's Crossing. Before the Chesapeake and Ohio tracks were raised in 1929 and a series of underpasses built, there were diamonds here where the streetcar tracks crossed the railroad tracks.