No, sorry, there isn't a way to have a colormap on uv set 0 and have a dirtmap which is scaled larger than the colormap. However, there is a way to get a colormap and a dirtmap on a street where both use the UVs of uv set 0. With this solution, you'll have to repeat the dirtmap as frequently as the colormap.
The street shapes, by default, have uv sets 1 and 2 defined as distance fields from the start/end of the street, as defined in the doc here:
Street and intersection shape UV—Help | ArcGIS
However, if you want to override this behavoir, you can delete the UVs on uv set 1 or 2. Then, since the UVs are not defined, the UVs of uv set 0 will be used. This way, you can set a dirtmap (or bumpmap). This does not copy the UVs of uv set 0 to uv set 2. The UVs of uv set 2 will not exist. This means, you cannot use them for splits, and you cannot use them as the distance field from the start/end of the street. For example, the standard street rule in ESRI.lib uses distance fields in uv sets 1 and 2.
In this code, the colormap and the dirtmap use the UVs from uv-set 0.
Street -->
set(material.colormap, "builtin:uvtest.png")
deleteUV(2)
set(material.dirtmap, "/ESRI.lib/assets/General/Dirtmap/dirtmap_1.jpg")