Along an “unclassified” highway, there may be some houses with large distances between them (but it’s not necessary that there are houses at all); with a residential highway, houses are quite close to each other, typically the compounds next to each other (and with “houses”, I mean building where people live, not barns or stables). If the highway leads to single residential building only, service may be used instead.
Most unclassified/residential highways in Malaysia are paved, but some are still unpaved.
Tracks are for agricultural/forestry access. If there are buildings along them, they may be barns or stables. If there are residential buildings, it’s not a track, but a residential/unclassified/service.
