I've been a railfan for years and have read occasional references to railroads' "running tracks." Excuse my ignorance, but I really don't know what this refers to. Running track as opposed to . . .?
"Running Tracks" are designated as such in the employee timetables. They may be of assigned direction or no assigned direction and are under the control of a designated employee whether train dispatcher, block operator, or yardmaster. There is usually no signal system involved, and all moves are made at restricted or reduced speed. It is necessary to report clear when leaving the track.
"Running Track" is used as opposed to "Secondary Track", "Industrial Track", or "Yard Track" in various employee timetables and rule books.