This discussion took place enough times, and, other than the fact that people developing mods for Advtrains would likely have to work around most of Advtrains to raise the speed limit (considering the context that W3RQ01 was asking for suggestions for his trains), the problems mentioned quite a long time ago are still relevant:
yw05 wrote: ↑Tue Aug 09, 2022 13:54
- From my understanding, certain callback mechanisms have undefined behavior when run across a long distance in a single step. This is one of the main reasons behind dtime clipping.
- The train HUD may need considerable rework for a speed of over 100m/s.
- Signals may be set too early, which is a problem for (for example) exit signals.
- World loading may become a problem for servers. (If you do not want this behavior, please look at the hyperloop mod instead)
To summarize the follow-ups back then (and to address some things I overlooked):
- The train HUD likely needs rework even before raising the max speed to over 100m/s, due to the fact that the number of digits for the LZB point distant indicator will likely need to be increased, and some modifications will be needed to provide higher precision, if wanted. The horizontal speed indicator will also need to be changed for higher precision at lower speeds.
- The problem with the signal being set "too early" is related to the problem where, in certain cases, approaching a signal at a high speed may cause the signal to be set before ARS is disabled on the train, such as near stations. Fixing this will likely involve some work on LZB or even the train movement algorithm in general.
- World loading becomes a problem only when a player is in a train. However, such a player would likely move faster than the server is able to catch up with mapblock loading, meaning that the client would likely not see anything around the train, hence the reason I mentioned the hyperloop mod (which, as I recall, waits for a moment and then teleports the player to the destination instead of moving the player along the tube). This is also affected by other factors, however, so it is hard to give a generalized limit on how high Advtrains' max speed should be raised to while keeping the effect of this low.
Maybe we can try and change train speed to be proportional to Advtrains max speed?
It could be possible to export the max speed variable, but this would have certain consequences if this variable was changed for some reason, unless we use some workarounds to avoid this.