Check out 50 speed limit 3D model on CGTrader for $2. High-quality mesh by cagdasc: 35268 polys, 105804 vertices.
SKP (Sketchup, filesize: 1.51 MB), BLEND (Blender, filesize: 3.62 MB), OBJ (OBJ, filesize: 2.32 MB), FBX (Autodesk FBX, filesize: 737 KB), GLTF (glTF, filesize: 1.29 MB), DAE (Collada, filesize: 2.55 MB), STL (Stereolithography, filesize: 1.68 MB), ABC (Alembic, filesize: 2.14 MB)