[OSM-talk] TAG-Suggestion: highway:trailer_shipment

Ulf Lamping ulf.lamping at googlemail.com
Sat Jan 16 02:18:45 GMT 2010


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 ;-)




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