This voting fix that general defenition of tag ‘highway’ should be “importance for the road grid (hierarchical position in the interconnecting network) instead of physical attributes”.
Wide used approach when ‘highway’ may be increase or decrease by one level when its quality is very good or very bad. The most common case is upgrading ‘trunk’ to ‘motorway’ when ‘trunk’ have some extra attributes.
But I agree with remark about roads formally classificated as European or Asian routes but which are not in fact because they cross disputed regions. Therefore we could not link to official classification and use more common rules from Key:highway page.
In additional to my previous proposal I’d like also upgrade to ‘trunk’ the most popular road go from Russia to Erevan (Armenia) via Tbilisi.
