Installation: put the contents in your Feldberg folder in game location on the HDD '..\AssettoCorsa\content\tracks\feldberg". It does not change any of your current files, only adds a layout "Feldbergring 2ways traffic"
With this additional layout you can use Track day / Weekend for driving in AI traffic. I didn`t limit the speed of AI so it`s as competitive as in race. You could limit it if you like - unpack the "ai_hints.7z" in "..\AssettoCorsa\content\tracks\feldberg\feldberg_2ways\data" to get the AI to obey a max 110 kph limit or edit the .ini to read whatever speed you fancy.
The additional feature of Custom Shaders Patch - "AI Flood" can be used too if you want a denser traffic around you. Make sure in such case to enable these:
If you want to use the wet variant of the track for 2-ways traffic, copying just the "fast_lane.ai" to the wet layout can do it for you. To keep the wet 1-way for later you can rename/move/pack the default "fast_lane.ai" beforehand.
If you have trouble loading the layout edit this line of "models_feldberg_2ways.ini"
to the name of the actual "physics*.kn5" that you have in