Both textures shown above are pbr textures of asphalt, except the quality is vastly different.
If you are making special meshes will doing an auto uv unwrap may seem like the way to go, sometimes like in this example, doing a custom UV unwrap can really help you.
In this case, the left mesh has an auto uv unwrap while the right has a special uv unwrap where I gave the top (visible side) almost all the space in the uv unwrap. Doing this can allow the visible side to be much higher quality, at the sacrifice of the sides you won’t ever see.
Roblox has pretty strict rules for textures being downscaled to 1k and if you are texturing a large object like a road piece in the image, this strategy can really help you get the best quality with a small change.
NewTestCube.fbx (14.6 KB)
You can see how the UV unwrap works where the top gets most of the space, also as a tip you should import PBR textures through the Asset Manager since its faster and can do multiple textures automatically without having to manually add textures!
Happy Texturing!