The problem of synchronizing repeat values of map and alphaMap in MeshStandardMaterial

Hello.

I want the texture to be tiled on a wide map.
Roads are very large on the terrain, but most of them are not marked.
So, I planned to use an alphamap to tile the road and only mask the necessary parts.
However, there was a problem that the repeat values ​​of map and alphamap were synchronized.
How can I solve this problem?