Often one wants to map an historic street or disused railway line. In either case they may be: overbuilt with newer construction; converted for "hiking" paths; tourist attractions; or a significant element on maps of local history. They are often easily identified by e.g. sunken roads, embankments, cuttings, bridges and tunnels in the area. Thus arises the need to explicitly record these features in the detailed mapping of the site. It may be inappropriate to use a tag like highway=historic, because there could be a modern feature (e.g. a footpath) in that location. In that case "overlaying an historic street or railway" is an additional property of a route already recorded as a Relation.
historic = road -> former road historic = railway -> dismantled railway
Other Tags specific to Roads
type = route route = historic historic = road
designation = altstrasse (historic road) cattledrive name = Fosse Way (regionally/nationally recognised Name) (enter local names on the individual Ways if necessary) origin = prehistory (occupied by e.g. burial mounds, also Celtic / pre-Roman roads) roman (Roman roads) medieval (documented) postroad (often unmetalled country roads) chaussee (former highway, 17th-19th centuries) motorway (disused, possibly degraded) significance = continental (e.g. Silk Road, Amber Road) national (e.g. Watling Street, Ermine Street) regional (e.g. Fosse Way, Ridgeway, most country back roads) local (e.g. previous local routes cut off or overgrown after later construction) wikipedia = en:Fosse Way
Other Tags specific to Railways
type = route route = historic historic = railway
railway = abandoned name = Great Central Railway gauge = 1435 (track gauge in mm) wikipedia = en:Great Central Railway
For the purpose of map display, 'line' (in the best case uninterrupted ) is the normal form of display for old roads. If you want to tag bridges or special objects in connection with the historic road, they should be recorded as independent objects and assigned to the relation via "roles".
role = bridge (historic bridge with visible remains, or at an accurately recorded location) bridge_hypoth (bridge at a location suspected by historians) post_release (historic post office, staging post) hostel (other overnight accommodation for travellers) ruins (other ruins associated with the historic road) stone (milestone, kilometer, hour or memorial stone associated with the historic road) (the exact type to be documented with the object)
Please document any additions here!
The overriding requirement to be considered an Historic Road is that there is an existing article in the Wikipedia category "Historical Roads"; such roads generally have at least regional significance. Local cattle drives can be tagged with designation = cattle_drive.
Alte Heerstraße Neuhof - Fulda http://www.openstreetmap.org/browse/relation/3218427
Alte Straße Antsanvia - Naxburg: http://www.openstreetmap.org/browse/relation/3218488
Rennstraße Taunus http://www.openstreetmap.org/browse/relation/3186583
Nassauische Kleinbahn http://www.openstreetmap.org/browse/relation/1765740