Proposed features/Relation:tmc/TMC Areas

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TMC Areas
Proposal status: Draft (under way)
Proposed by: MHohmann
Tagging: type=tmc:area
Applies to: relation
Definition: TMC area locations

Rendered as: No particular rendering
Drafted on: 2014-03-26

This is the third stage of the TMC proposal. Goal of the overall proposal is to find a simple, useful, understandable and easily maintainable mapping scheme for TMC location codes. These codes allow a connection between TMC traffic guidance messages and OSM objects, so that OSM based navigation systems can calculate their routes under consideration of traffic messages. Goal of this third stage is to find a mapping scheme for TMC areas, which are used, for example, for weather warnings.


In this stage of the TMC proposal TMC area locations are to be mapped. These can be administrative areas, meteorological regions, industrial / urban areas or any other type of area. Each TMC area location, which is uniquely identified by a country ID, table code and location code, should correspond to exactly one TMC relation in OSM. The TMC area relation should describe the geographical outline of the corresponding TMC area.


TMC area locations are often used in TMC messages such as weather information or other hazard warnings which are not restricted to a particular road or junction, but apply to an extended area such as an administrative area, meteorological region or industrial / urban area. The boundaries of these areas are not contained in the TMC location code lists. In order to identify an area, a routing or navigation application therefore needs a different source of information in order to decide whether a weather warning is relevant for the driver or not. This can be done my mapping the boundaries of TMC areas as proposed here.


Every TMC area, which is uniquely identified by a country ID, table code and location code, should be mapped using one relation tagged as type=tmc:area. The members and tags of this relation should be as follows.

Relation members

The members of a TMC area relation should describe the geographical outline of this area. There are two ways how a TMC area can be mapped: either by adding already existing boundary or multipolygon relations as members to the TMC area relation, or by adding ways which form a closed boundary of the area.

Required tags

The following tags should be present in any TMC area relation:

  • type=tmc:area - Marks this relation as a TMC area.
  • table=* - Country ID (cid) and table code (tabcd) of the TMC location code table in the form {cid}:{tabcd} (e.g., 58:1 for Germany).
  • version=* - Version of the TMC location code table according to which this area is mapped (e.g., 13.0 for the table issued in Germany 2014).
  • lcd=* - Location code of this TMC area.
  • class=* - Class, type and subtype of this TMC area in the form {class}{type}.{subtype} (see TMC/Location Code List/Location Types#Area location types for a list of possible values).

Optional combinations

Some TMC areas have names listed in the location code tables. These can be tagged as follows:

  • name=* - Name of this TMC area.

If this area is part of another TMC area, the location code of the containing area can e tagged as follows:

Affected tags

No other tags are affected by this proposal.


Please use the discussion page for comments on this stage of the proposal and the discussion page of the complete TMC proposal for comments on the overall TMC tagging concept.