@wyo You misunderstand the very concept of OSM. Nobody rules or enforces laws on his own. National communities and consensus are important. We have a national consensus here, with room for future improvement. Please stop interfering.
You can’t disregard local circomstances and habits. The same road surface can have different levels of importance in different countries. We would never call a dirtroad a highway. Simply because is isn’t in NL.
The same is true for aqueducts: yes we have some. But the majority is simply a tunnel with a souped-up name.
As for world-wide mapping rules: they don’t exist but are guidlines. And even if I would follow the wike for aqueducts, based on the examples given I would conclude most of our tunnels are indeed no aqueduct.
There might be some interpretation anywhere yet never in the cases I’ve mapped. The rules mentioned in the OSM wiki do correctly apply to any of the objects.
There’s always an argument about local consensus. When the locale consensus violates the general rules then the local consensus has to be adjusted and not my mapping.
I’ve never mapped any object named “…tunnel”. Also I’ve never mapped any object which I haven’t seen at least once. Believe me I know what I do.
Being an obstacle is not a hint for aqueducts. Sometimes aqueducts are, sometimes aren’t.
True. I’m no sacrosanct against mapping for rendering. But when it comes to lead to miss interpretation then correct mapping has priority. Aqueducts are such important features they have to be on maps even if rendering isn’t appropriate. Just think of an ordinary building tagged as a church, nobody would ever consider removing this tag.
I’ve several times said if one thinks of mapping a tunnel under an aqueduct, then do it but never remove the aqueduct. This is perfectly well with the general rules.
Why do a temporary mapping when correct mapping is possible. This is a silly proposition. No renderer will ever consider and use temporary mapping.
We are now back to the question: Why to Nederlands mapper not map aqueducts as aqueducts? So far not a single argument which makes sense has come up.
I do mostly mapping of waterways not only in NL but also in other countries. So I’ve a rather good idea of what I do. I’m not closed to any sensible argument if they are given. Just look up the discussion about Marrekite naming. So far there isn’t any regarding aqueducts. Locale consensus doesn’t apply since there isn’t any argument for it either. Therefore general rules apply and these are rather clear.
As a reader who hasn’t yet formed an opinon on this matter it is a bit hard to get a good view of the actual remaining arguments between all the accusations. And even if we disagree, we are all in this because we enjoy mapping and the results of it.
@ Wyo:
thanks for contributing to waterway information in the Netherlands and contatcting this forum. You seem to make some interesting points, but I think the way you formulate them (starting with the title of this thread) might cause other people to get on the defensive rather than to listen and evaluate your agruments.
I for one was curious to your answer about the arguments for not tagging the Calais-Dovert tunnel as an a aqueduct given the arguments you propose.
@Dutch posters: let’s not forget that in both directions things might get lost or misunderstood in translation and maybe it’s good sometimes to have a fresh set of foreign eyes questioning the things that we have grown accustomed to, so we can re-evaluate to assess if this is still the way to go for us.
Roads can quite easily be constructed to ‘make a dive’ under a construction, waterways can’t. Therefore ‘waterway over waterway’ needs a typical bridge-construction while the water-road-aqueducts in The Netherlands are build as an inclusive construction where the infrastructural changes are usually bigger for the way beneath (the road) than for the way above (the water).
In other words: Dutch aqueducts are mainly constructed in the ground in stead of above the ground.
And why this one is called Prinses Margriettunnel? https://www.google.nl/maps/@52.9990757,5.7056668,298m/data=!3m1!1e3
Also, it is quite common in The Netherlands to refer to an aqueduct as a tunnnel.
Now it gets confusing. Should we decide which is what on the basis of the construction and its dimensions or on the basis of the name?
Really? Maybe you can share the photos you’ve taken when you sailed over all the aqueducts in The Netherlands.
You think JeroenHoek comes from Mars or something?
I can confirm that a lot of Dutch and Frisian people do use the word tunnel when referring to an aqueduct. The word bridge on the other hand is not much used. The thing is that people here tend to refer to the whole construction that makes the crossing of road and waterway possible. Users of the road under/through the aqueduct see a lot of concrete construction and users of the waterway don’t see much of it. That’s a major factor in how people experience and name such an object.
Just look at these pictures:
https://en.wikipedia.org/wiki/Aqueduct_(bridge)
https://en.wikipedia.org/wiki/Aqueduct_(bridge)
Dutch aqueducts are not anything like that.
Please stop pretending as if things called aqueducts are in essence all the same.
You are assuming things about Dutch infrastructure and disregard the knowledge of real Dutch and Frisian people.
I don’t. Yet the kind of surface doesn’t decide on the type of road. A road connecting two cites is anywhere tagged as a primary road regardless if paved or not or in NL or Africa. Neither does any sensible mapper map a dirt road a track as long as it connects two cities used for ordinary vehicles. Mapping might be different on different location but seldom as much to lead to wrong interpretation.
Come on, you can’t mean that really. Aqueducts in NL aren’t that much different than in e.g. DE or FR. Aqueducts are aqueducts, that’s no question. Anything else is just …
As i tried to illustrate here :
https://forum.openstreetmap.org/viewtopic.php?pid=722688#p722688
the situation with aquaducts in the Netherlands is unusual in polder/boezem-areas, since the water does not lie at the lowest level, but above the land level.
And as a result water does not flow down, but is pumped up: first from polder to boezem, then from boezem to open water, which can be up to 9 meters.
Then please share or link some photos of aqueducts in Germany and France so we can see how comparable they are.
Sorry if I overreacted a little bit in this thread, it wasn’t easy to argue sensible when others don’t. Maybe this is more clear when looked at the history.
- First I noticed that some of my mappings disappeared. Okay probably made a mistake so I made them again in smaller changesets
- Then my aqueducts disappeared this time with a comment which I couldn’t grasp the meaning
- Okay I started a thread in “Questions and Answers” (https://forum.openstreetmap.org/viewtopic.php?id=63985) were I got the feeling I’ve mapped correct.
- Next again disappearing aqueducts. A little upset the next thread in “Germany” (https://forum.openstreetmap.org/viewtopic.php?id=64239). Again “kreuzschnabel”'s answers showed I haven’t done much wrong.
- And now hear were I seems to get no real arguments except for local consensus which is IMO wrong
I have to said I’m really disappointed about how mappers here fuss about something which should never have been discussed. There’s nothing won to insist of locale separation. Sorry I can’t understand you. I still think mapping of aqueducts should be done as outlined on top of this thread all over the world including NL.
I’ve decided not to map any aqueducts in NL anymore. I don’t know if I keep on mapping other things in NL.
Good luck
What could I’ve said to that statement! What would you have said when accused in that way?
The fact that you don’t agree does not mean the arguments did not exist. Local (national) consensus is not wrong, it’s how we agree to do things for now in this country. If you do not agree, you can weigh in, but not dictator-style. Please refrain from further mapping in this way.
The biggest problem is your claim:
Anyone else acknowledges there are different types of constructions that are called aqueducts. Just read the first two sentences on the English Wikipedia page: “Bridges for conveying water, called aqueducts or water bridges, are constructed to convey watercourses across gaps such as valleys or ravines. The term aqueduct may also be used to refer to the entire watercourse, as well as the bridge.”
Sentence 1: Most aqueducts in The Netherlands don’t fit this description.
Sentence 2: Different use of the term aqueduct.
Cases where a waterway is created, raised or substantially altered by the construction of an aqueduct are rare in The Netherlands. The waterways are almost always already there. The roads are the ways that are constructed newly or differently. You could even called them ‘inverted viaducts’ because the roads are being ‘led’ more than the water. For the waterway there is only the change of surface from natural materials to artificial.
Maybe not for you but for most other people the objective and history of elements do help define what it is.
By the way, this is very common in OSM: highway=primary is about objective, waterway=river and waterway=stream are about history, and these are just a few easy examples.
Something else that you haven’t adressed:
For us a tunnel-tag on the road means that the infrastructural situation is tagged: the crossing of a waterway above a road or a road underneath a waterway. But then you get upset because according to you your ‘mapping of an aqueduct’ is made undone. For you the tunnel-tag on a road is optional but for us this tag marks the whole infrastructural situation called ‘aqueduct’!
LOL …
sometimes there are some morons on the exact words →
At least the Dutch translation aquaduct is the most correct … 
https://nl.wikipedia.org/wiki/Aquaduct_(watergang)
De Friese spelling vind ik het mooist 
oei… English thread I like the Frisian spelling at most
@Wyo: I hope you don’t stop mapping in the Netherlands, regardless the outcome of this discussion.
I hope that I would not have felt that as an accusation, but as a question that led me to evaluate my reasoning and conclusions and perhaps as an opportunity to show and explain to the people I’m discussing with that they misunderstood my arguments.
After giving it some thought I would guess that the problem lies with the bold marked section:
most of the the things called “aquaducten” in The Netherlands are often not clearly seen as bridges by the local community, and I agree with that, and I think the reason is, As Andries pointed out that these are not new waterways drawn over existing landscapes, by new roads that are led under existing waterways
But as an exception I guess most of us would would see this one as a bridge, since it spans 4 roads and two water areas (you’re right about that)
https://www.mapillary.com/map/im/Ep32f8lO1bH62knQ9UIMOg
https://www.mapillary.com/map/im/RnRQYHu0bG-BFCZfdjCjxg
(as a canoeist I do have time for pictures 
With the bridge criterium not working for most aquaducten in the Netherlands there remains the criterium of “transporting some water above some air and something else” and in that regard the Dover-Calais tunnel (which I regard as a very different beast as well) is no different from aquaducten.
Personally I agree that Dutch aquaducten should be mapped in OSM as bridge=aqueduct on the waterway, but based on arguments formulated a bit differently.
The main aspect they share with each other and also the classical aqueduct between two hills over existing land is that the waterway is contained by an artificial, free standing ‘Flussbett’ (bedding).
In the case of the Netherlands the waterway might have already been there before there was an aqueduct, but in making the aqueduct an
freestanding artificial bedding replaced the original bedding (instead of digging below the waterway or sinking a tunnel tube for the road).
For example see from 10:15 in this time lapse of the construction of the Limes Aquaduct in the Oude Rijn (A4):
https://www.youtube.com/watch?v=OeC1YYanIxg
Or this animation from 2:00
https://www.youtube.com/watch?v=am0uPK9MnzE
The difference between a regular tunnel is generally visible both from the water and from the road.
But given the fact that the road goes down and under an existing waterway, I also agree with most Dutch mappers that a tunnel-tag on the road should be used.
I think the “Do however avoid using both a bridge tag for the upper way and a tunnel for the lower way for the same crossing.” should yield here. As you say, its not a strict law. Since the special circumstances and different perspectives of looking at aquaducten shown here, I think it shoud be interprted as “avoid when you can, but use if you must”.
For the (water-)ways that should solve it I think (if anyone finds the rendering on the waterway ugly, please make a suggestion at OSM-Carto).
The area’s are something else, still figuring some things out about that, but I agree with Andries and Peter that we should be carefull not activly doing things that cannot -with changes reasonably possible- be rendered properly and mess up our main map.
The rendering for a waterway with bridge-tag works as it should though: rendering a small blue line above the road. It just shouldn’t be used together with an area (natural=water).
You are willing to break the rule ‘avoid tagging both a bridge and a tunnel for the same element’ but also the general rule ‘one feature, one element’ is already broken by mapping a canal both as area and as a way. The latter may be accepted practise but then the same can be said about mapping a Dutch aqueduct as a tunnel for the underlying roads.
And what is the reason for accepting the combination of an area natural=water with a way waterway=*?
Is it not because the way normally doesn’t disturb the rendering of the area?
Yes, I think that the fact that it can be rendered without problems plays a role, but I think the principal reason -although not documented very clearly- is that linear elements are used to describe routable networks and areas to describe “landcover”.
With highways the linear elements are usually used for both, since we generally don’t mind ways being over-representated on the map, given how important we regard them (which shows ugly blanks after zooming in, I fully support tagging areas representing roads now that we have the sources).
You see some start with (normal) bridges being tagged as an area (man_made=bridge) while there is also a linear element for the highway across it with a bridge=yes tag
But I think nobody would propose deleting the linear highway-element after an more infromative area with “man_made-bridge” (with only that one highway) is added and the highway-tags are transferred.
Water tagging starts with either areas for the big lakes and linear elements as a quick and dirty fix for smaller ditches/canals, but routable (not necessarily navigable) linear networks are also formed, for example to describe how rivers relate to each other.
So I think linear and area representations of the some objects are commonly accepted next to each other, given their different goals and in area-tagging highways are just dragging a bit behind the waterways in this regard (-;
However the page for "one feature…"could have some additions to reflect this current usage.
Ik denk dat dit verder wel in het Nederlands kan.
I agree with your post. The thing is that just as we accept certain things for routing purposes (‘being pragmatic’) we could and should, I think, accept some things for rendering purposes. Because you could also say: “no tagging for the router! Let the developers of routing software find a way to handle areas!”.
I don’t see why a node on the waterway denoting the aqueduct wouldn’t be satisfying for routing purposes (a new seamark-tag for this would be nice).
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Persoonlijk zou ik graag zien dat sommige areas routable worden. Dat zou voor voetrouting door een pedestrian are helpen, en path door een weiland of stuk heide, en waterway door een water area. Heel veel ways worden zo immers als dummy redundant getekend, alleen maar omdat areas zogenaamd niet overgestoken kunnen worden.
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Je kan aan een lijn domweg niet zien wat het echt is, dus moet je aannames doen en extra tags toevoegen. Zoals het voorbeeld van de polderslootjes laat zien, is dat niet realistisch: afhankelijk van zoomniveau zie je bijna alleen maar water of bijna geen water.
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Als je het water als area tekent, en het loopt door een aquaduct, zou je het moeten versmallen tot de echte breedte en zou taggen als aqu[e|a]duct betekenen: render de zijkantjes met een hard lijntje. Meer niet, toch? Of er dan een waterway overheen loopt boeit verder weinig, die heeft geen boodschap aan de zijkant. Vaargegevens zoals max diepgang moet je wel taggen op de waterway, maar dat moet je zonder aquaduct ook.
Als je ooit kan routeren over waterareas kan je ook daar de diepgang wel opzetten trouwens. -
Als er een weg onderdoor loopt boeit het voor de weg eigenlijk niet of hij onder water, spoor, olieleidingen of onder iets anders of helemaal nergens onderdoor loopt. Dus aquaduct hoef je niet op de onderdoorweg te taggen. En voor het aquaduct boeit het eigenlijk niet wat er onderdoor loopt of dat er helemaal niets onderdoor loopt. Je kan op dat stuk weg een tag zetten die het stuk weg het best beschrijft, zonder je druk te maken over wat eroverheen loopt. Is het iets met dichte/harde zijkanten, dan graag over die lengte een mooi hard lijntje aan de buitenkant van het wegtracee.
Tunnel als het duidelijk een tunnel is of tunnel genoemd wordt, tunnelbak als het grotendeels open is behalve waar het aquaduct oversteekt, en een passende andere kreet als het nog iets anders is waar je echt met tunnel/tunnelbak niet wegkomt. Niet gemapt, dat is dan een tekort op de kaart maar er gaat niks fout.
Als je het stuk weg waar het aquaduct overheen gaat maar geen aquduct, viadukt, spoorviadukt of bridge gaat noemen, lijkt mij.
Okay lets discuss the Calais-Dover situation seriously:
- Any air on top of the road belongs to the tunnel, there’s no single strip of air which belongs not to the tunnel
- It is named “tunnel”
- On the water there’s no visible hint that one is passing on a bridge
Summary: 3:0 This is a tunnel and no aqueduct
- Amstel acuaduct
- There’s no air not belonging to the tunnel
- It is named “adeduct”
- A bridge might or might not be visible on the water
Summary: 1:1 Problably a draw meaning tunnel=yes and aqueduct=?
- Leeuwarden acueducts:
- I don’t know if there’s some air which doesn’t belong to the tunnel I assume not
- It’s named “awadukt”
- It’s clearly visible as a bridge on the water
Summary: 1:2 meaning tunnel=yes and bridge=aqueduct
- Mid-Fries Aqwadukt
- There’s lot of air not belonging to a tunnel (neither motorway nor cycleway), it’s not even visible as a tunnel but a bridge
- It’s named “Aqwadukt”
- It’s clearly visible as a bridge on the water
Summary: 0:3 meaning tunnel=no and bridge=aqueduct
- Prinses Margriettunnel
- I don’t know if there’s air beside the tunnel
- It’s named “tunnel”
- I don’t know but suspect it’s visible as a bridge
Summary: Probably 2:1
This is so far the only case where it’s not clear what should be mapped. From the road aspect it’s obvious a tunnel and not an aqueduct while from the touristic aspect it’s a tunnel and an aqueduct.
The difference to the Leeuwarden objects aren’t that different. I probably would map it equally. Same goes for the Mid-Fries Aqwadukt or similar objects, a tunnel=yes is acceptable since people might think of a tunnel.
New or not doesn’t change anything on the definition of aqueduct, transporting some water across some air. New is only that there are passing some other things with the water. Locale people using these objects on a rather daily basis don’t care what these objects are yet foreigners do. I prefer mapping for people not used to a local situation.