I've tried to keep a game instance open for a while, pausing instead of closing the game, for about 48h.
Play time maybe 10-14h, didn't keep track. Memory image >5GB (Fresh load of the same save is 3GB in RAM), game gets sluggish, closing it took ages and a force close in the end.
Attaching the log, and the savegame in case it's not a problem of the long run time in the first place, but something with the setup there.
A lot of "~Sim: Path finder crazy busy: XX tasks is waiting in the queue." where 25 < XX < 40.
22-01-03_03-48-24_8939.log
The Beach, 323 years, 109 vehicles.
The Beach_ Great Coal Line.save
Files not imported: The Beach_ Great Coal Line.save