Dear Roland Many thanks for your comments.
Now I see how difficult it is for public transit.Yet I wonder if a public transport graph is more realistic? >A relation can carry one or all directions of a bus line. In the former case, >I recommend to keep both the itinerary (the way the bus physically takes) and >the bus stops, usually nodes of type "highway=bus_stop", in the order in which >they are served. In the latter case, you often find a big mess on both the >itinerary and the bus stops which are left from former times (API 0.5) when >there was no defined order on the elements of relations. Do you think it is possible to get bus stops (includes the origin and destination point) in order in a route through any geometry method? Regards, Grace -------------------------------------------------- From: <[email protected]> Sent: Wednesday, February 10, 2010 1:00 PM To: <[email protected]> Subject: Talk-transit Digest, Vol 14, Issue 4 > Send Talk-transit mailing list submissions to > [email protected] > > To subscribe or unsubscribe via the World Wide Web, visit > http://lists.openstreetmap.org/listinfo/talk-transit > or, via email, send a message with subject or body 'help' to > [email protected] > > You can reach the person managing the list at > [email protected] > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of Talk-transit digest..." > > > Today's Topics: > > 1. Re: Help: Bus Stop Data Extraction for Bus Routing Service > (Roland Olbricht) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Tue, 9 Feb 2010 14:28:46 +0100 > From: Roland Olbricht <[email protected]> > Subject: Re: [Talk-transit] Help: Bus Stop Data Extraction for Bus > Routing Service > To: "Public transport/transit/shared taxi related topics" > <[email protected]> > Message-ID: <[email protected]> > Content-Type: Text/Plain; charset="utf-8" > > Dear Grace, > >> We would like to extract public transport data for public transit routing >> service in Sweden. > > This will be a difficult, maybe impossible task at the moment. Public > transport data are a complicated matter. Most important for you might be that > there is no timetable information in the OSM database. Thus, without a data > source for the timetable information, it is not useful for public transport > *routing*. Buses running only a few times a week or only on school days can't > be discriminated from regular services running every few minutes. > > Also, there is not even a standard for a public transport data model for bus > services in OSM. The best possible approach known to me is > http://wiki.openstreetmap.org/wiki/User:Oxomoa/Public_transport_schema > But there might be a quasi-standard for Sweden differing from this one, > depending on your local community. Please provide some IDs of example > relations of the data. > > I'll try to answer to you based on the data model commonly used in Germany > (e.g. Wuppertal) or France (e.g. Grenoble). > >> What is the difference between the stop nodes within a relation and the >> nodes tagged as ?bus_stop? in highways which are also contained in a >> relation? > [...] >> Do the stop nodes within a relation merely refer to the passenger waiting >> point, whereas, stops in highway contained in a relation represent the >> vehicle stopping points? > > In general, the node tagged as "highway=bus_stop" indicates the position of > the road sign or shelter and is off the street. If I find such nodes on the > street, I move them to their proper position. For the vehicle stop, the node > on the street might be tagged as "public_transport=stop_position" but they > rarely exist (almost 500,000 bus stops in the database versus 9000 stop > positions) or aren't even defined (stop positions in my area depend on the > vehicle design, not the served line). The stop areas are introduced to group > all the bus stops having the same name. > > A relation can carry one or all directions of a bus line. In the former case, > I recommend to keep both the itinerary (the way the bus physically takes) and > the bus stops, usually nodes of type "highway=bus_stop", in the order in > which > they are served. In the latter case, you often find a big mess on both the > itinerary and the bus stops which are left from former times (API 0.5) when > there was no defined order on the elements of relations. > > Cheers, > > Roland > > > > ------------------------------ > > _______________________________________________ > Talk-transit mailing list > [email protected] > http://lists.openstreetmap.org/listinfo/talk-transit > > > End of Talk-transit Digest, Vol 14, Issue 4 > ******************************************* > _______________________________________________ Talk-transit mailing list [email protected] http://lists.openstreetmap.org/listinfo/talk-transit
