2.6 alpha 1768 or later
Configuration file: tsignals on/off
Command line: -ZQ
This switch requires PathBasedSignalling.
Allows PBS reservations the opposite way through selected one-way signals.
The signal GUI is used to set this property. ExperimentalFeatures:Alpha. The button to use is that to the right of the semaphore<-->light signal button.
In order to visually distinguish these signals, and for an icon to be present in the relevant signal GUI button, a signal GRF must be present which defines the required signal sprites. Such a GRF can be found: here.
A signal which is defined as a through signal is automatically set to a be PBS signal.
Two-way signals are unaffected by setting them as through signals.
Note that a train will never wait when heading the opposite way through a one-way through signal.
Hence they should be used where trains should pass through in one direction, and possibly wait in the other.
Bi-directional station layouts.
The signals on either side of the station platforms can be set to one-way through signals, such that the normal direction of signals, is outward from the platform.
Hence trains will reserve a route past and through the station-entrance signal on their way-in, such that two trains cannot reserve a route into the same platform and deadlocks can be prevented.
A sample image is shown below.
This feature was contributed by Jonathan G. Rennison (JGR).