Dark territory is a term used in the North American
railroad industry to describe a section of running
track not controlled by
signals.
Train movements in dark territory were previously handled by
timetable and train order operation, but since the widespread adoption of two way radio communications these have been replaced by
track warrants and
direct traffic control, with
train dispatchers managing train movements directly. Today most dark territory consists of lightly used secondary branch lines and industrial tracks with speeds ranging between and ; however, there do exist a small minority of main lines that fall into the category. The term can also apply to
automatic signaled lines where trains are running against the normal flow of traffic.