I forgot to login as I wrote the first message. Following the street away from the town I also bumpt into an unclassified road (440166116) so I think some features are already altered from the data source. I am afraid as I am not a local that someone does not like my changes. Changing tags when the area/country is consistently map this way may cause more problems than it solves.

In regions where responsible authorities do not provide recent, complete or satisfactorily cathegorized data about streets, like rural areas of Afrika there is an attempt to use the unclassified tag as soon as a road connects "between settlements" if no hierachy is known.

Clearly that is not the case here but if there is no equivalent cathegorization available for this region, I would use unclassified until the last settlement before a street ends for streets that are currently residential or not mach to tertirary. Therfore the residential tag for internal connections inside settlements are distinguishable from the more wider road network. But I am not sure if I am the right person for this area.