SideTracked event caches have gone, departed, left the station. Everyone is very sad, so, WaitingRoom Events have been initiated for the train buffs who like a meet up at a station.
To qualify as a WaitingRoom Event, they will need to be held or take place near a station of some sort, and I'm sure, given enough events held someone will step forward to keep an eye on statistics. For now just enjoy the beverage of your choice and the company these events will bring!