IRL you often see signal aspects take a couple of seconds to change, and sometimes in an "interesting" way, e.g. (I'm going to use UK signalling here) you may get green + red both on for a moment, or the feather might light up before the red changes to green, or the train may have almost passed before the green goes red. This can happen for all sorts of reasons (simple explanation for the latter for instance is that the track circuit is some distance ahead of the signal). Those who know about modding - is it practicable do you think to easily create a mod pack that would do this? I'm not necessarily asking you to - I'm willing in principle to learn how to do this (I'm a software engineer but in a totally different field) - but from your knowledge is it doable?
Well, Armstrong Powerhouse have done that for TSC. As these signals are Lua scripted, you can do pretty much anything. Not sure about TSW though, it's maybe something for londonmidland ? The question is rather: are these scripts accessible for modders or not?
In most signalling systems this is done intentionally, it may take a bit until all parts of the signal and accessories are properly lit, so the remaining restrictive aspect still being up tells you that the signal is not finished yet. Imagine german entrance signal, it will light up two bulbs in the distant signal, communicate with exit signal, update the distant signal to reflect it, light up few bulbs in the main aspect, light up dozen of bulbs in the speed reduction board, cross-check that all bulbs are lit correctly, that's a lot of work for 70 years old electromechanical technology. Also when something goes wrong during setting the signal (bulb breaks), the restrictive aspect will never go dark even for a moment. When changing from permissive to restrictive aspect (after the train passed), this phase is often skipped and the aspect changes more or less in one step. Zusi and Simrail both have this behavior beautifully simulated. Things like bulb breaking are no longer an issue on new signals though, so the LED ones often change instantly.
That makes a lot of sense. I hadn't really thought about "why" these things happen and the sense it was deliberate. But if it is then even more reason it'd be great to simulate, if it is going to be practicable...
