Hi Oleg, thank you for posting both updates and answers.
As far as I can see, the current ground texture system uses a network of borderlines that look organic but repeat fairly often over the terrain. The area within one set of borderlines is then filled with an appropriate texture (golf course / field a / field b / field c / farm / forest / village / city / industry ) and with the appropriate models (vegetation, buildings etc). Then the borders themselves are applied, these being hedges, paths, roads etc. For a quasi procedural texture system, I believe this is one of the best solutions available, and your results look overall very nice. However, the system does not look too good when such a field is cut by a railroad. Screenshot No. 3 illustrates my point. The REAL geometry (railroad lines, big highways) does fit badly into the texture when compared to the basic borderlines. The only solution I can imagine would be to treat such a road / railway line as yet another borderline, and apply different textures to the different segments that have been divided by this geometry. It would not be perfect, but it could be coded, and it would make these roads and railways fit better into the landskape, making them both blend better into it and be more visible in that they change the landscape around them.
The mockup picture below illustrates my point.
Flutter
