[Talk-transit] Making bus lines more specific

Robin Däneke robin at daeneke.at
Tue Apr 28 13:41:26 UTC 2020


Sorry, I sent this mail only to Dave, sending it to the list for reference too.



> -It is a current, valid tag that's more detailed, clear, precise & more popular than PTv2 equivalent.

That needs 100 other tags in other tagging families to make any sense, and hence helps to clutter up the database. I feel like many forget: OSM is not a map, it is a database. And sidenote: there are axioms/rules on what not to do in a database. OSM is the best example for any of those. 

> Platforms should only be mapped if there's a clear, raised section of pavement for boarding a bus/tram. In OSM we map the physical world.

More and more stops have these. If we do not want the platform to be a simple way to say „public transport stops here“ but as this „real world“ definition, then that should be only even used when micro mapping, not as a general tag, but it is used as a general tag, so your definition is just not the tag definition, as that would not be allowed to be a node then...

> highway=bus_stop is far more "dedicated" than public_transport=platform which require further tags to clarify.

if relations are correctly used (as they should be in a database) no elaborating tag is needed on the single platform.

> Oh dear.
> PTv2 was sold as a complete schema, fully formed with no requirements for amendments, yet there are these frequent proposals to tweak.

Because no one shouted at each mapper that didn’t adopt the voted for scheme, so many kept mapping in old ways or mixed it wrongly. Also, the old tags were kept carefully instead of booting them out when they shuld have left the dataset 9 years ago. Now that we have the problem, we should solve it and not be so ignorant and conservative of the mixed bag of screw-up that this has become. 

> PTv2 adds nothing but extra tags & confusion. It runs in parallel to a schema which has worked well since the OSMs inception. 

To me, the singular highway=bus_stop nodes that were strewn across the countryside, on the side of many roads with no name tags, no relations and nothing else, has not worked in the slightest. It worked as much, if not less, than how p_t:v2 could work if everybody would have moved to it in 2010.

Public transport is a complex topic. It is surely not as easy as mapping „amenity=waste_basket“ or „highway=street_lamp“. It has it’s complex sides, and especially because of that there should not be 100 low level tags to determine the type of something but rather one easy-to-map general one (for buses, trams, trains, boats, aerialways… alike) to map the area where people wait (as this is ALWAYS the same thing, a platform in one valid sense) and deal with what stops there in the more complex part (relations), without which, public_transport mapping is useless and could be stopped instantly.

> Time to drop it completely.

No, public_transport is its own category that deserves its own tags. Especially as the railway=* tags have quite a lot of technical and operational sub-tags, that have nothing to do with passenger transit. We should definitely have an own category for the, to most people important kind of transport. Disconnected from more technical tagging families.

That is my rational here.

Whatever I come up with (and will ask for constructive critisism about here) in the future shall be, what p_t:v2 didn’t even try to be. The p_t-community made, small attempts at best to make it „the solution“ it was supposed to be. I am fighting with this inbetween state since that scheme came into existence. Could we please finally fix it, and then have it properly accepted (maybe with technical aid of OSMF/DWG) almost 10 years later? Is that truely much to ask for?

KR
RobinD

PS: In public transport, there are some things (like routes) that make sense in the database, but do not, as such, exist physically. The „we map the real world“ is such an outdated view. The world of relevant geo-referenced data has become to big to just map trash cans and trees. Because the OSM wouldn’t be much more, if not also some theoretical concepts would have made it into it. I am sure we could discuss the definition of what a building is, how a company is a „real“ thing or whatever, but that would be besides this topic.


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