Railroad with wood sleepers modeled in any detail. The pack contains 6 LODs. 4K PBR (Metalness/Roughness workflow) Textures allow to acheive insane details.
Every Mesh has different material IDs to distinguis the rails from sleepers and gravel, for absolutely highest material quality. Inside 3ds max file only the LOD0 has the visibility toggled on, to get other LODs simply toggle on the visibility from layers editor window.