This has been around for years maybe, in all versions of the game. The railroad gravel texture does not blend with the environment - at all. If you go prone and look closely, you can see the 3d-model of the gravel hovering above ground. The color and the resolution of the gravel is also really different from its surroundings, and has a really sharp edge, like it was a completely separate entity from the environment. Also, maybe some light/bump map or something would bring some life to the rocks in that texture, since everything about it is really breaking the immersion imo. Otherwise the updates to the environment are really starting to look good.
The game has railroad in many different locations, so it would make sense for you to make it blend in as well as possible, like the roads, paths, etc.