You don't need attendants on rail at all - what is there for them to do? For flight you need them to oversee preparing for a crash trains should get this failure mode should be designed out - which does imply doing the regular maintenance and using good safety systems. Just give a small discount to anyone with current first aid/CPR and you can be sure there are more than enough regular riders to take care of the remaining issues.
Even if you do decide you want attendants for some reason, train should stop not less than once an hour, which means the crews can get off the train after 4 hours and staff the one back home. (I don't believe freight rail shouldn't do the same, but they have different operations from passenger rail such that more than an hour between stops might be reasonable)
Note that if the train really is going through the middle of nowhere at one hour you just pick a random dot on the map and grant it a station just to get your stops. The cost to stopping a train is less than 5 minutes for the full trip (this adds up if you stop every few km, but when it is once an hour it isn't a big deal)