Approach Lit Signals

[AndiS]

Doing a quick hack to implement automatic block signals, I strayed into the field of approach lit signals.

The clear bits:

Approach lighting on routes with signals for two parallel tracks when there is a train in the parallel track will not happen. You would need extra links at every signal and I don't think there is enough interest for that at the moment.

Routes that have one track per direction are easy when it comes to the main signal. Green is not shown. All other aspects are shown. Approach lit signals are assumed to be automatic signals. So as soon as the train does not need block protection any more, the red is switched of and the green is not switched on.

If we have 3-aspect signals, yellow is shown even if no train approaches, simply because red is shown ahead and you need a warning for that.


Not so clear to me:

The timing when there are distants. The distant is lit when the train is X metres away. Is the main signal lit at the same time, or only later when the train is X metres from it?