ProMods

Is the big junction near Hamburg one big prefab?

Nope. Everything that's not a cloverleaf, trumpet, diamond interchange is most likely a custom interchange. These are built with smaller pieces that allows us to make custom connections...

Oh, ok, thanks. And do you know if it's possible to make prefabs with Blender2SCS, or can that only be done with ZModeller?

Zmodeller yes but I wouldn't even want to start on it. It takes alot of work. This system with smaller parts is alot easier.

It's not possible with Blender2SCS. The conversion can't handle metadata and paths from the PPD files and only loads the model itself. The only thing you can do is changing the look of the model a bit... but even then you need some deep PMD editing to correct the material references (some materials don't like the conversion process by Blender2SCS).