Splitting ferry routes?

Posted by thilo on 25 March 2017 in English (English).

I just took a look at this changeset:

Which made me briefly wonder, what kind of large scale editing did he do to cause such a large changeset bounding box?

It turns out, the reason was probably a locally restricted change in Tarott that affected the endpoint of a very long ferry route:

It’s not a very severe problem, but still somewhat unfortunate because it can make detection of illegitimate or problematic edits significantly harder. Therefore I propose to split all long distance ferry routes into at least three parts, split at the borders of the territorial waters of the involved countries. This would result in rather short parts near the ports, and a long part through international waters, where it probably won’t matter as much.

I’d like to hear some thoughts about this, especially from people who, as creators of long distance shipping routes, have a stake in this. Any obvious downsides that I haven’t thought of?


Comment from Aces California on 25 March 2017 at 17:57

I can get behind this because I’ve worked on my ferry’s just today, and I’ve been putting off fixing it for weeks because of those bounding boxes. They are just an unwieldy size in general and kinda clogs up looking at recent change-sets for a region if your looking for what has been recently added. I mean there’s other ways around it, but it’s just something small that bugs me.

Comment from mstr on 25 March 2017 at 18:03

Hi thilo,

unfortunately I did it the same way in the past, just modeling a single way from port to port, because it’s the simplest way to do it, I never thought about alternatives. By splitting up into 3 parts we avoid such a large changeset bounding box only in the case that nodes at a port are changed, am I right? Does it happen very often? I think, compared to this situation, it’s quite common that someone really edits long routes or uploads several small changes at locations far away from each other which results in large changeset bounding box as well (that’s what I see in eastern Uletha). The drawback of splitting the way is that an additional relatin is needed in the case that you want to link the route to the wiki or is there another way I haven’t thought of?

Comment from wangi on 25 March 2017 at 19:38

Why are they even mapped? Local ferries I understand, but shipping lines, cruises?

Comment from Aces California on 25 March 2017 at 20:20

I suppose that is even one thing to consider Wangi, and goes back into the discussion on aesthetics/realism/or detail. Do you want to map to aesthetics in that if a cruise-line or shipping-line or whatever crossing vast-distances look attractive, to map to OSM standards on using the ferry tag for ferries only, or to map cruise-lines and shipping-lines to add even more detail.

Here’s an idea just off top of my head and outside the box, but maybe for mapping stuff on that scale. I don’t see what else could be that scale apart from borders and coastlines, but at the scale of size of what we have seen. But maybe we should have some form of average guide-lines or tutorial so people don’t go over-board with the ferry tag?

Comment from Leowezy on 25 March 2017 at 22:18

I think as long as we don’t start mapping flight corridors on the standard layer (and I hope we’ll never do so) zick-zacking across the globe, we shouldn’t attempt to map any more or less frequent shipping route. It’s quite pointless, as these routes don’t represent any actually built infrastructure. Nearly everything on the map either represents a tangible thing in the real world (a building, a road, a forest) or gives further information about these things (pictograms, names etc.). I don’t see why we should start mapping shipping routes, with one exception; where they pose a significant option as a public mode of transport, and these ships are called ferries ;)

(Sorry for the confusing writing, I can’t really get my thoughts on track)

Comment from histor on 25 March 2017 at 23:56

In real world not exist only ferries but too regulairy lines of freight-shipping over long distances. On maps and world-atlasses you can see this lines. So this lines can be a tool to connect countries ot different users in OGF together. One of the first lines was from Porto Colon /Latina to First Harbor in Orinoco in 2013 and the starting point, to set embassies in the land of the partner of the trading line. So seen this shipping-lines are a connecting element between OGF-users.

To handle this lines the better way is, to put all pieces (one, three or more) of a line in a route-relation

Comment from mstr on 26 March 2017 at 00:09

Actually we do not “start” mapping, these routes are already present around the whole globe. Comparison to flight corridors does not make much sense, since flights usually are at a different level. In my opinion, there is a huge difference between OSM and OGF. OSM maps real existing objects: we simply place a pattern “building” and a name “tour Eiffel” and everybody knows what it is, OGF could include more details. To me it is very interesting to see waterways with much or almost no traffic. But I also accept that someone else might be interested in some other aspects. I will continue with such things, even if they are not “OSM-like”, until the Higher Mapping and Tagging Court finally convicts me.

Comment from Luciano on 26 March 2017 at 01:36

I think there is no problem mapping them, even if they are not part of the “OSM standard” - because, as histor and others have said, they are interesting things and allow a basis of interchange between our OGF countries.

However, I also think making them into a single long way is a bad idea, for the reasons Thilo pointed out at the start - when you touch them, that makes for changesets that cover vast areas.

So the solution is as some have pointed out - make route relations. If people do this diligently, we could even get a sea-transport data set that could make for an interesting addition to our own OGF transport layer, or people could make interactive “slippy” leaflet maps on the wiki.

Comment from Leowezy on 26 March 2017 at 09:35

In hindsight my comment seems unnecessarily harsh; I hope I din’t affront anyone. I just wanted to express why I personally am quite lazy when it comes to mapping such international shipping routes, but I can see why other users find them very useful ;)

Comment from histor on 26 March 2017 at 10:02

If you remember, that (in real life) 95% of all intercontinential trade is moved by ships, so this regulary shipping-lines have a certain importance. Sure - there are a lot of tramp-ships sailing at occassion from port to port - but most run at regulary routes - and this regulary routes are more comfortable p.e. for a producer in country X_ with regulary export in country Y. So this shipping-routes may have some importance in the OGF-world and sure you may use them or not.

But if someone create a shipping line - then please in a straigt and logical way. Some lines I have smoothed and corrected last month in southern Tarephia before seemed to be lines of drunken captains. And near the harbour please set soft curves. A great ship may have a turning-radius of several kilometers.

Comment from isleño on 26 March 2017 at 19:35

But if someone create a shipping line - then please in a straigt and logical way. Some lines I have smoothed and corrected last month in southern Tarephia before seemed to be lines of drunken captains. And near the harbour please set soft curves. A great ship may have a turning-radius of several kilometers.

Totally agree. I’ve added notes to the wiki articles that long distance lines are recommended for advanced users only. Shipping lines are not easy!

Comment from wangi on 27 March 2017 at 10:58

So, where there are currently many lines within close proximity - should then all instead be using relations, and a single way?

Comment from histor on 27 March 2017 at 16:21

How many ways a shipping-route can be, is a question of overlook - see the first comment of thilo. I prefer more ways for a route for the reason, that if one of the ways may be damanged, then the other will stay allright. If you show at your relation for the route, you can control the integrity of the shipping-line.

Comment from wangi on 28 March 2017 at 13:17

Understood - if a single route uses more individual ways, in a relation, then small modifications to it should result in a localised changeset, rather than one over half the globe.

I was just thinking ahead - just now there are ~2300 ways tagged as route=shipping. At many places a lot of these come together, running parallel, for long stretches. I think what should happen is the common sections should be a single way, which is then used within the relation of the individual routes.

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