roadとかひとつひとつにmesh colliderつけたら
Failed to extract collision data: Submesh 0 uses unsupported primitive type
"Quads". Please use either "TriangleStrip" or "Triangles".
Please make sure you have unchecked "Keep Quads" on your model's Import Settings.
Mesh asset path "Assets/ZRNAssets/005135_16321_1_1/Models/Osaka_Ground.fbx" Mesh name "_road_A"
というのが出てエラーになりました。