On 01/24/2011 10:16 AM, Dominik Mahrer (Teddy) wrote:
On 01/22/2011 08:38 PM, Michał Borsuk wrote:
On 01/22/2011 09:32 AM, Dominik Mahrer (Teddy) wrote:
The more exact the OSM map is, the
more likely it is that the two directions do not share the same way for
the both directions (the lines of one street are split up).
Again, this is not an argument as OSM is not a routing software, but a
map.
Exactly, OSM is a map. And on a map I want to be able to read the route
of a public transport service.
We've exchanged arguments in this field before, let me present an actual
example from your area that shows the level of complication of
modern-day timetables (and Zürich actually is still quite traditional in
that matter):
Here's an excerpt from the ZVV timetable for Bus 210, uptown Zürich:
line_nbr,route
201,557
201,558
Bus 210 consists of two routes, 557 and 558. Sounds easy, doesn't it?
Route 557 would be mapped in OSM as route in one direction, and route
558 as the opposite. Indeed, it is so:
route,stop_name
557,Uitikon, Wängi
557,Uitikon, Gläseren
557,Uitikon, Roracher
557,Uitikon, Dorf
557,Uitikon, Halde
557,Uitikon Waldegg, Post
557,Uitikon Waldegg, Neuhaus
557,Ringlikon, Langwis
557,Ringlikon, Dorf
557,Ringlikon, Sonnhalde
557,Uitikon Waldegg, Bahnhof
...and...
558,Uitikon Waldegg, Bahnhof
558,Uitikon Waldegg, Neuhaus
558,Uitikon Waldegg, Post
558,Uitikon, Halde
558,Uitikon, Dorf
558,Uitikon, Roracher
558,Uitikon, Gläseren
558,Uitikon, Wängi
So far, so good. Let's then take a tram line, I selected a *random* stop
in the centre of Zürich, and *randomly* took tram line 10. Here's the
list of routes and their conditions:
line_nbr,route,nbr_or_runs
10,120,56
10,124,50
10,121,12
10,122,12
10,125,6
10,407,6
10,410,6
10,413,6
10,417,6
10,411,3
10,412,3
10,414,3
10,415,3
10,418,3
10,420,3
10,702,2
10,703,2
10,123,1
10,126,1
10,408,1
10,409,1
10,416,1
10,419,1
This single line contains *23* different routes! Twenty-three routes are
hidden under one "tram line". Now even if we ignore the routes on which
the tram runs 1, 2 or 3 times a day, then we still have *nine* routes
(nbr_or_runs: 56,50,12,12,5×6).
Surely not all of them have different paths, but I guess some do. And
that's just for a random line in a big city.
Now take a small city: 300 thousand people spread over big area. Bus
lines around me that normally consist of several relations. Most of
those can be ignored, they are very early morning routes, or they follow
the same path, but many do not, they are simply very different
variations, 4 different paths per direction is nothing unusual over
here, detours for school runs are neither (more paths!).
My intention is to show to you all that times of tram/bus lines where
the vehicle started at point A, drove to point B, and so throughout the
day are slowly over. You won't be able to map your favourite line on
OSM, unless it's as simple as the bus 201 shown above. And then what do
we do with the more complicated lines? We're supposed to make a standard
that would accommodate many different PT systems.
So again, my suggestion is to map all variants in both direction as one
relation, because we can't show the desired level of details anyway, and
leave the rest to the routing layer/software/website, whatever.
It is perfectly possible to combine then real timetable data with OSM,
to create a multicolour maps and other eye candy.
Greetings,
LMB
_______________________________________________
Talk-transit mailing list
[email protected]
http://lists.openstreetmap.org/listinfo/talk-transit
