I backup route and session files as *.cdp files to an external hard drive. Now to Trainz's built-in process:
I once tried to recover a route from TrainZ's native backup ... without success !
There were a series of posts on this very topic since the process changed somewhat for TRS22. Thanks to JCitron for figuring it out. I have not checked to see if the wiki was updated or not for TRS22 backup restores, if not, try this, which I wrote for my own use as a result of advice from JCitron.
How to restore Trainz 22 automatic route backups
1. Using Content Manager, determine the kuid number of the route you want to restore.
2. Using File Explorer, find the Trainz data folder. If you don't know where it is, Launcher/Train Settings/Install tab will show the local data folder. Open the folder and click on backups.
3. Click on the date you want to restore from.
4. Find a file that looks like this: kuid nnnnnn nnnnnn.tzarc_xxxxxxxxxx where nnnnnn nnnnnn is the kuid number of the route and xxxxxxxxxx is some random number.
5. Copy that file to the editing folder.
6. Rename the file to eliminate everything after "tzarc".
7. In Trainz Launcher, click on Manage Content. Filter to Today. You should see an item with a date and time.
8. Perform a Developer/Rebuild Database.
9. When the rebuild database completes, you should see your restored route. It will have a status of Open for Edit. Right click on the route and perform a Submit Edits. You can delete the miscellaneous item with a date and time (see #7 above).
10. Close Content Management, start up Trainz, and you should see your restored route.
So my advice is backup to an external hard drive AND learn how to use Trainz's process as well.