In the German OSM forum there is an ongoing discussion how to replace the current and illegible TMC mapping by a more robust and understandable tagging scheme:
http://forum.openstreetmap.org/viewtopic.php?id=23754This seems like a nice opportunity for us to bring in some ideas on which TMC information we would need / like to have in OSM, so that it can be implemented in Navit. I found this ticket:
http://trac.navit-project.org/ticket/570It seems that so far we have a "traffic distortion" feature which allows to add traffic distortions into the routing graph. However, there is no automated source of this data yet. Instead the user has to add this information manually. The missing parts would thus be to get TMC data from an RDS receiver or some other source, process it, locate it on the map and finally add the traffic distortion as specified. The first part would be simple, if the data just comes from a COM port / character device / pipe. Processing the data would also be simple, one just needs to implement the ISO 14819-2 TMC event code standard, which is very clear. It consists of messages or events, which describe what has happened and contains "location codes", i.e., numbers from a table, which describe locations such as motorway exits or roundabouts. The third part is contained in the ISO 14819-3 location code standard and depends on the tagging used in OSM. Finally, the last part can be easy or difficult, it depends on how easy it is in the code to add a traffic distortion, but at least it should be manageable.
Since there is no agreement on a TMC tagging scheme yet, does anyone have suggestions what it should look like? Which tags would we need?
(on hardware level)
