@RolloS03 : I had in the description some mods I used. I put their link too.
Just tell me if everything is right on your side.

I'll check if it works with these mods, I'll let you know;)

@RolloS03 : I just play a game and it works nicely.
Perhaps you need to get some mods on as : Move It!, Road Anarchy tool too.
These mods are often "on" on my side, perhaps that' is the reason.
By the way, I was checking without those mods when I put "off" during the game and I can put this asset too.
So, I do not know why is not working on your side even the if the place is not so flat.
At last, all "Périph" I did in the list I put on the description was made with the latest version of Cities Skylines and the new DLC Sunset Harbor.
Sorry for my broken English and I hope your are going to understand it.

@RolloS03 : I will see on my side and I will keep you inform.
All the Ring Road assets I realized, the land must be fully flat for better use.
By the way, I advice you to use Move It! mod.

I can't put the object. he writes that the terrain is too steep although it is very flat, practically 100% level