Landuse (in its original development) was supposed to denote the agricultural "use" of a piece of land, like an orchard, a vineyard, a production forest etc.
Gradually, more and more (and also contradicting) "landuses" came available, leading to many controversial situations.
At some point the use of landcover was proposed, mostly to create the difference e.g. between grass on a farmland (landuse) and grass in a soccer stadium (landcover).
landuse=* (in my opinion) shouldn't be used to describe highways because there is a solution I have given in my previous reply.
OSM suffers from way too many "solutions" for the same problem, try to avoid adding another one!

Kind regards
Marc.