* Side line Single track lines with single track and '''only one train''' going back and forth crossing the . Here such a line crosses a main (double-tracked) line. Without the crossing, there wouldn't have to be any signals on such side line. But to prevent above described self-block, there must be signals on '''each segment'''. Since the track is used in both directions by one train only, these must be bi-directional signals. (If there is more than one train using such sideline, bridge must be used instead of the crossing so no signals would need to be placed; otherwise the trains would get stuck nose-to-nose at the bi-directional signal eventually. )

* '''End Terminal station''' with multiple platforms (no trains entering the station from the other end)with multiple platforms. If you send more trains than the number of platforms, there '''must be please see chain signal''' at the entry switch, where the next train will wait, if all platforms are occupiedsignals below.