[Talk-transit] Ideas for a simplified public transportation scheme
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Sun May 12 18:28:24 UTC 2019
On 09-05-19 23:03, Markus wrote:
> On Tue, 7 May 2019 at 21:15, Jarek Piórkowski <jarek at piorkowski.ca> wrote:
>> 7c. From what I'm understand, this bus stop node does not have to be
>> connected to a pedestrian highway either, with routers presumably
>> jumping from the nearest highway?
> Yes, this is what OsmAnd does.
>> 8. A stop_location (to use ptv2 terminology) on the way that vehicles
>> travel on could help with things like calculating and showing the
>> likely route the bus will take, but this can also be calculated
>> without the stop_location node by projection of other stop objects
>> onto the way
> It can be calculated. So why complicating mapping and maintaining
> public transportation routes needlessly? :)
Because sometimes it can't (think of a fence or ditch between ways that
is not mapped - besides, for renderers it is relatively hard to
calculate whether there is something between a node and a way and
whether that constitutes a barrier.
Please take note that the stop_position is _optional_ in PTv2! It
doesn't need to be mapped!
>> 9. There are some cases that do not cleanly fit into hw=bus_stop
>> "PTv1" tagging, for example a sign-only stop served by both buses and
>> trams, or a waiting platform served by both buses and trams
>> 9a. Because we must retain hw=bus_stop per #3 and #5, any
>> accommodation of these cases must either be initially of tags, or
>> guidance on how to place highway=bus_stop tags
> If we go for the "improved PTv1" solution, my suggestion  was to
> place both highway=bus_stop and railway=tram_stop beside the road.
> Thus, highway=bus_stop and railway=tram_stop can and should be
> combined on one node.
The PTv2 solution has this all and unifies tram and buses, while not
being more complicated than bidirectional PTv1, except it has some
optional features that make things unambiguous in difficult cases...
>> 10. Meaning of public_transit=platform tag is dependent on context, it
>> unifies/duplicates some existing tags, arguably it sometimes describes
>> imaginary things, and it is disliked by many editors
> As i understand it , public_transit=platform does not describe
> imaginary things. On a node, it means the waiting area of a stop
> (i.e., it is equivalent to highway=bus_stop or railway=tram_stop), and
> on a way or area, it means a real platform that acts as a stop (i.e.,
> it is a combination of highway=bus_stop/railway=tram_stop and
> However, in my opinion it would have been better to create a tag like
> public_transport=stop that -- as with all other tags -- always
> (regardless of whether used on a node, way or area) means the same
> thing (waiting area of a stop) and that could be used in combination
> with highway=platform/railway=platform if there is a platform.
I think that is being pedantic. In The Netherlands, most "platform" bus
stops can not be discerned from a normal sidewalk if not for a slightly
raised kerb or block markings that have a second meaning of parking
(within a certain distance of that marking).
To check whether someone is in the dirt or on pavement, one could always
add a surface tag to the platform.
>> 12. Many of the currently mapped tram systems have a railway=tram_stop
>> + public_transport=stop_position node on the rail, so we should
>> probably not change this scheme either without good reason
> I think that a simpler mapping and maintaining of the routes as well
> as a better routing are good reasons enough. :)
As well as unification of tram and bus mapping (and train for the same
>> 13. There is currently no clear way for tagging stops that also have
>> physical platforms, except for PTv2
>> 13a. This exists as physical feature in real world and should be
>> supported, in a manner compatible with platform-less stops
>> 13b. Should we add bus_stop/tram_stop on one of the nodes of the
>> platform way ? Next to the platform? As pointed out by Markus, we
>> can't do what might be the most intuitive method of the platform
>> way/area sharing bus_stop tag because the platform is also a highway=
> In my opinion, if we decide to stick with PTv1 tags, the best way
> would be to add a highway=bus_stop or railway=tram_stop in the middle
> of the highway/railway=platform way or area.
I don't understand what you mean here, with add a highway=bus_stop in
the middle of what? Of the highway way where the bus drives, or in the
middle of the highway=platform way?
Why would we need this double-tagging of a way:highway=platform +
Wouldn't it be simpler to have one tag that has the semantic meaning of
"place where one waits to board/alights" that has the same meaning
whether it is one spot, a linear element or an area, whether it is for a
bus, tram or train? That would be public_transport=platform!
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