OSMWiki 
Separation from roads

It is acceptable to map landuse to stop at the boundary of roads, and it is also acceptable for landuse to overlap road area on roads where the right of way is not significant enough to warrant a break in the landuse area.
It is strongly discouraged to glue landuse to road lines. Glued landuse makes the data much harder to work with. It is better to have the landuse boundary stop at the edge of the road, the edge of right of way, or overlap the road completely. 

 Using highway centrelines

Another approach that some mappers have taken is to either draw land use polygons that extend over the public highway sharing nodes with highway centrelines, or to fragment the highway network and create land use areas from relations of the fragments. While this results in less drawn geometry subsequent editing is more complicated. This increases the risk of damaging not only the land use areas but also the highway network. It is also less accurate, extending adjoining land uses over land that is dedicated to the public highway.

