How to tag the public transport zones?


What is the best practice to describe the public transport zones in OSM?


According to the discussion about Residenzpflicht (in german) I would say that public transport zones are not geodata. So they should not be mapped within OSM. You can set up an own project and include the information there.

But I’m new here and would be interested in what other people think.

I agree - they are similar to public transport schedules; the information generally comes directly from an import in any case. So any application needing to use them can always pick up the latest from the source.

A number of zones were imported in the UK from NAPTAN data, the so-called PlusBus zones. No one has found a use for them, and in any case they seem to be based on convex hulls around public transport stops. All the NaPTAN data also has the zone to which each stop belongs, so in practice I think if you want to map this, add the information to the stops. You need a convention to handle stops in more than one area, and duplicate refs across different Public Transport bodies.

Some of this information is suitable for OSM, but not necessarily all (for instance I hold a Network SE railcard which entitles me to reduced tickets in SE England: the relevant zone probably includes half of all British train stations).

An alternative way to map may be to only map the stations/stops at the periphery of the zone which would involve much less data to maintain. However there are probably plenty of special cases of specific transport modes which extend outside the standard area and may not be stop based.