[2020] I have to reload the game any time i place, remove, or edit roads, rails, transport, etc.

To see if it's the save or something to do with your mods, try starting a new test city. You can just have Unlock All on so you can build train stations right away. If it doesn't happen in the test city, then it's your save that we need to look at. If it does happen there too, then we will need to look at your mods. :)

I just had a look through your mods.

- Auto Line Color is broken, use AutoLineColor Redux instead
- Automatic Emptying and Empty It! conflict - pick one and remove the other
- Extended Public Transport UI is old, broken and no longer needed. Remove it
- Achieve It! and Mod Achievement Enabler overlap. There is no point in having both and they might conflict. Remove one.

Your issues might be related to that, so try and fix those, restart the game and see if things behave properly then.

Does it also happen in a new city if you make one to test? Or is it only happening in a specific save?

Originally posted by 1upnate: just this specific save. a new city with the same set of mods doesn't exhibit the same behavior

That sounds like something is wonky with the save then. Let's try a few mods that can clear up issues - even though your city doesn't have those exact symptoms, it's worth a try.

Get these mods and make sure they're all enabled:

https://steamcommunity.com/sharedfiles/filedetails/?id=529129546
https://steamcommunity.com/sharedfiles/filedetails/?id=1620588636
https://steamcommunity.com/sharedfiles/filedetails/?id=667342976

Then restart the game to make sure they're all running correctly, and go into Options, find the Loading Screen Mod on the left, and enable the options for Safe Mode.

You don't actually have any simulation errors, or at least it doesn't sound like it, but hopefully they will still help.

Once your city loads, save it as a new file, then restart the game and remove the mods (you can ofc leave the Loading Screen Mod on, just make sure the Safe Mode options are off again).

Then try to load that new save normally and see if the problem is still there.