Tag:route=road
 route = road
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| Description |
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Relation type used to combine road sections. 
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| Group: routes |
| Used on these elements |
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| Requires |
| Useful combination |
| See also |
| Status: de facto |
| Tools for this tag |
A route=road relation specifies that its members are a part of a road network and are used for motor vehicle traffic. This relation is mainly used for major routes which have a ref=*. A value for ref=* may be unique in a smaller area (such as a city), but not in a larger area (such as a country); adding roads to a relation allows to distinguish parts of roads that are related and to make roles between parts of roads explicit. Most urban streets and minor roads which are identified only by a name=* tag do not belong to a relation.
Rationale
Originally, OSM only modeled a highway route as ref=* on each individual highway=* way. In Great Britain, the authorities officially assign numbers to roads (akin to naming them); they also designate routes but leave them unnumbered. Other communities throughout the world have attempted to model their route networks similarly but have run into many difficulties because of a conceptual mismatch with the real world.
Some workarounds have arisen over the years. The ref=* tag contained an alphabetic prefix to distinguish the route from similarly numbered routes in other networks. In case of a concurrency, the ways would have loc_ref=*, reg_ref=*, nat_ref=*, and/or int_ref=*, or ref=* would contain a semicolon. All this requires data consumers to guess the network based on extensive heuristics including geocoding and hard-coded numeric ranges. Renderers that chose custom highway shields based on these heuristics often got them wrong in surprising parts of the world.
Route relations model highway routes more explicitly and robustly, handling many common cases that are simply infeasible with ways alone:
- In case of a route concurrency, the
highway=*ways are members of multiple route relations. network=*can distinguish as many route networks as necessary within the same jurisdiction and can distinguish similarly named networks in different jurisdictions.- In case of an extraterritorial route, a country namespace in
network=*prevents data consumers from assigning the route to the wrong country. - Data consumers are responsible for reconstructing the route's systematic name or its abbreviated form based on
network=*. This avoids petty disputes over punctuation. - A gap in a route relation is easier to detect. If the gap is intentional, the relation ID makes it easier to document the gap.
Members
See the route relation wiki for applicable members.
Special tags
Relations tagged route=road may have the following tags in addition to the ones described in Relations/Routes:
| Name | Discussion |
|---|---|
| TMC:cid_(CID):tabcd_(TABCD):LocationCode | ID number transmitted in variable message signs that identifies this road. See TMC_Import_Germany and TMC:LocationCode=* for TMC locations.
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Software support
See Relation:route#Software support.
Possible tagging mistakes
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The attribute |
See also
- Relations/Routes for another way how to tag routes.
- Relation:route#Road_routes types of road-networks this route may be a part of
scenic=*- Additional mark for scenic roads- Relation:street