Am 15.01.2010 23:02, schrieb Carsten Moeller: > yes, osm relations are one possible solution. But from the view of a > pgRouter it is a very stony way to collect that data back into a routing > table. You are right, that there should be a tag like "terminal" or > "ramp" or even simpler "link".
Seems there's at least no "difference in principle" that this would be useful :-) We already have the established amenity=ferry_terminal and an amenity=motorail_terminal wouldn't be very different in functionality - no need to develop a complete new name IMHO. As you certainly want to have a different rendering for these two, it might not be a good idea to have just a single tag like amenity=terminal for this. > From the perspective of a "street map" a pickapack railway or ferry has > the same quality as e.g. highway=pedestrian. Sorry, i don't get your point here. On highway=pedestrian I'm not allowed to drive (except maybe for un-/loading at specific times) - which is completely different IMHO. > So I'd prefer sth. like highway=railway, highway=ferry, > highway=railway_link and highway=ferry_link. > This info is enough for pgRouting to create a topology. > Additional properties can be assigned to "amenity" or "railway" of course. For a ferry (if all is tagged well), this can already be achieved. You'll travel: highway=service amenity=ferry_terminal (if it allows cargo=vehicle) ferry route (as tagged and displayed already on the maps) amenity=ferry_terminal (again with cargo=vehicle) highway=service The same principle applies for a railway as well: highway=service amenity=motorail_terminal motorail route (see below) amenity=motorail_terminal highway=service The exception for the railway - compared with ferries - is, that the "railway grid" will physically connect a lot of places. There's certainly a physical railway connection from the sylt shuttle mainland station to italy. But the railway company just won't offer you that service :-) Now you can invent a special tag (as you intended) for the short distance or "point to point" connections, like sylt shuttle, channel tunnel and alike applies for several short distance tunnel services in the alps. Then you'll need *another* mechanism for the long distance travel from hamburg to vienna (Deutsche Bahn is offering about roughly 20 such dedicated routes - not more) with just exactly the same problem: Travel with your car pickapack on a train from A to B. That's why I was thinking about relations. However, as you may want to display on a map only short distance but not long distance pickapack, it even makes sense IMO to have two different ways to tag this. One to tag "point to point" connections as you'd suggested and one for "long distance connection grid" connections using relations. May I suggest to just keep existing stuff for ferries and use amenity=motorail_terminal and highway=motorail (which seems to be the right translation for german Autoverladung/Autoreisezug) for the short distance ways? Regards, ULFL P.S: Next time, using the tagging mailing list seems more natural for these or similar discussions ;-) _______________________________________________ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk