Over the past few years, I’ve been mapping a lot of bus stops and routes. Over the past few months I’ve been looking around how it’s done in other places around the world.
What I find (this may of course be influenced by what I wanted to find) is that most bus stops start out as a node next to the way, tagged highway=bus_stop, usually with a name on it.
Then somebody comes along, who glues it to the way. Then somebody else comes along who maps a platform next to the way, using a way, copying all the tags over. They do this regardless of the whether a platform actually exists. They think they need this to add 2 objects per stop to the route relations. Somehow the wiki convinces them of the need for this.
Mapping platforms as ways where there aren’t actual platforms feels wrong to me. Adding a set of details to more than one object also doesn’t feel like the most sensible thing to do. Adding 2 objects to each route relation for 1 real life object makes working with these route relations harder to do.
I’d like to see that a casual mapper can start out mapping a bus stop as a node next to the way, as highway=bus_stop.
Possibly they add public_transport=platform to this node. It seems odd to do so, even if no platform is there, but that’s how things evolved. Tagging it as public_transport=platform means that a role platform will be assigned to it in the route relation. (if the route relation has public_transpot:version=2). It’s the answer I got when I asked the question a few years back on the mailing list. I usually put that node more or less where the pole is. But the exact position is not all that important, as long as it’s more or less where passengers will be waiting.
As far as I’m concerned this node is what represents the bus stop at this side of the street, so it seems obvious that this is the node that should be added to the route relations. The nice thing about doing it that way, is that there is no need to transfer details or relation membership from one object to another. This node is there for the lifetime of the stop. One object to work with, containing all the details, including directly available coordinates.
Now the stop_position nodes. First off, I don’t see a need to map all of them and since where I map bus lines they are not all present, I don’t see why we would add any of them to the route relations. No need to repeat the stop’s details on them either.
Then the platform ways. If there are actual platforms, I would tag them highway=platform/public_transport=platform. Nothing more, nothing less. No need to add them to the route relations.
Then the stop_area relations. This is where we get the chance to indicate which platform node(s) belongs to which stop_position node(s) (if mapped) and which platform way (if present). Doing it this way means to have such relations for each group, where a group is the ones on one side of the road or the ones belonging to 1 platform in a bus station. They can then be grouped in a hierarchy of stop_area_group relations, although this is only needed for the more complex ones and for bus stations.
Sometimes I wonder if I should create a proposal for this. Usually I give up before even getting started, as I know how hard it is to convince anyone in the OpenStreetMap universe, once they are set in their ways. Little by little I’m starting to build the courage to go ahead with it after all. Writing these diary entries is a small first step, also to see if there would be support for such a simpler way of mapping public transport.
Also don’t get me wrong, it’s still possible to fill in all the detail of the accomodation surrounding the bus stops, but in a way that builds further on what was mapped previously, instead of converting from one object type to another or needing to add details more than once.
토론
2017년 8월 17일 09:12에 JamesKingdom님의 의견
I would also like a more simple tag. Somebody has come to the area near me using OSMI and created duplicate nodes with
public_transport=stop_position
, and just dragged it to the nearest big road, even though most of these are wrong.2017년 8월 17일 16:25에 SomeoneElse님의 의견
I believe that the “more simple tag” is “highway=bus_stop”. In the UK it’s 33 times more likely to be used that public_transport=stop_position.
More complicated tagging isn’t “wrong” of course - but there’s no need to make things more complicated than they need to be. The only roadside public transport infrastructure in most of the UK are bus stops, so it makes sense to just map those.
2017년 8월 18일 09:44에 alan_gr님의 의견
I would also support a simple approach. The full “version 2” approach may work in places where there are lots of active mappers with an interest in public transport, but in many countries the priority should simply be to get bus stops mapped in the first place.
The comment by @SomeoneElse about the UK is interesting. I would guess that this situation is fairly self-sustaining - if a new mapper in the UK sees a consistent and simple approach already working in their area, they may well simply follow that without worrying too much about what the Wiki says. Then they see that their work gets rendered as expected, so they continue on those lines.
The problem seems to arise in countries that have got stuck somewhere between highway=bus_stop and a more complex “version 2” approach. Here a new mapper finds a confusing mix of approaches, turns to the wiki for help, and gets the impression that a simple “highway=bus_stop” is some kind of historical relic that should be avoided. (You would never guess from the wiki that a highly populated country such as the UK apparently still gets by using mainly this simple approach). So our new mapper tries to map platforms, stop positions, and stop areas, sometimes fighting with the limitations of their chosen editor to do so. Then they find that most of this work doesn’t get rendered in the standard map or the Transport Map layer, give up and go map something easier.
So I would love to see something simpler and more new-mapper-friendly. I am not clear if a new tagging approach is actually what is needed, or are the existing problems more with the combination of Wiki documentation / editor support / renderer support, rather than with the tags themselves?
2017년 8월 18일 10:02에 SomeoneElse님의 의견
@alan_gr Unfortunately, the wiki isn’t always “authoritative”. In https://lists.openstreetmap.org/pipermail/talk-gb/2017-August/020486.html I described a situation where I changed the wiki to reflect current practice, but it was changed back because current practice was “wrong”. My options at this point were to get into a wiki edit war (I’d probably win that, since I am through historical accident a wiki admin, but it would (a) be a very silly waste of everyone’s time and (b) something of an abuse of powers) or to get on with something more constructive, which is what I decided to do.
The best advice for new mappers is “stick with the editor presets”, and follow the iD editor walkthrough, which is a great introduction to “how to map”. In iD if you add a point and search for “bus stop”, a highway=bus_stop is exactly what you will get.
2017년 8월 18일 10:20에 Warin61님의 의견
Hi @Polyglot, Thanks for your help on that Katoomba bus route. I have not applied it yet to others .. too much to do!
On keeping it simple… Yes Please. The simpler the easier it is to understand, see where I have gone wrong and correct it. The easier it would be to translate too. However .. it is not just simply mapping bus stops .. the route/s are needed too so it can be seen where they go.
On sticking with editor presets… err no. Not everything is in presets. I use the OSMwik to guide me .. if I cannot understand it I simply leave it while my mind thinks on it. I may well read some more on the OSMwiki for similar things and look at what is on the map and see how that was done. I’d much rather think about what I’m doing that follow a preset or the OSMwiki.. particularly when some of them in the past have been, or are now, ridiculous (IMO). If I still cannot see how something is to be done then I ask for help, usually this works well.
2017년 8월 18일 10:28에 alan_gr님의 의견
@SomeoneElse - that is interesting about iD (I don’t use it often). In JOSM if you click the bus icon on the toolbar you only see “Stop Position”, “Platform”, and “Stop Area” options, so right from the start you have to figure out the differences between these three things and wonder on which of them you should put information such as network or operator. In the menus there is a separate “Public Transport (Legacy)” submenu for highway=bus_stop, which again seems to discourage actually using this option.
Does iD provide an option to add route information in some way? I think it may be at the stage of wanting to tie stops to routes that things get tricky for some people. I now think that highway=bus_stop nodes can be added to route relations, but at one stage I had the impression that I would have to use platforms and stop positions for this.
I agree that the wiki should be treated with a degree of caution, but it takes time to develop the confidence and knowledge to do this, and I suspect it is also more difficult to judge how far a given page may be prescriptive v descriptive if you are reading it in something other than your first language.
2017년 9월 13일 17:16에 alarobric님의 의견
I have some interest in mapping bus stops and have spent far too much time reading all the various wiki pages and proposals and getting quite confused by what the right approach would be. I’ve settled on just using highway=bus_stop, as I don’t see the value in any of the extra tagging. (Who’s going to use the stop_position for anything?) I’d love to see the wiki much clearer about various levels of transit mapping and to be more clear about the current state of affairs.