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Quest Modification: Height limit for railway crossings #5180

Closed gdprdatasubect closed 1 year ago

gdprdatasubect commented 1 year ago

Use case Expand Quest: "What is the height limit here?" to railway=level_crossing

Proposed Solution

Ask if there is a maxheight displayed via signs if no tag maxheight:signed=no and maxheight=default If there is a sign tag maxheight:signed=yes and ask the user for the corresponding value for maxheight

matkoniecz commented 1 year ago

In which countries it is commonly signed? In Poland for example signage is unusual in such cases.

mnalis commented 1 year ago

Yeah, it does sound strange to me too, how would it even look? Do you have a picture @gdprdatasubect ?

I've always understood that it is railway=level_crossing only if "a road crosses a railway on the same level; i.e., without a bridge" - and as it is level, there is not bridge/tunnel, so there should not be any height limits?

Taginfo says that only 0.12% of railway=level_crossing have maxheight=* tag, and the wiki does not mention that tag combination either.

gdprdatasubect commented 1 year ago

This is the one that probed my interest in this subject: image credit: "invest0r" here is another interesting, indirectly restricted one: image credit: google

The normal legal maxheight for vehicles in germany is 4 meters, however there are apparently some exceptions for agricultural vehicles.

mnalis commented 1 year ago

Thanks @gdprdatasubect, does this situation happen often in your country that railway=level_crossing has such height limitations? Can't say I've seen them much (or really at all) in Croatia.

Note quest guidelines, especially ":zzz: No spam" and ":clock4: Effort vs impact".

gdprdatasubect commented 1 year ago

grafik

https://overpass-turbo.eu/s/1yGC

I made an overpass query, all crossings that don't have have "4" or similar tagged as maxheight are red. 4.5 seems standard in the eastern block, so i gave it a different colour

France seems to have more data than germany, there it is more varied with everything from 3.2m to 4.7m: grafik

The Standard for Sweden seems to be float handling errors :D This would maybe be an good example where the tagging for maxheight:signed=yes could come in handy? grafik

arrival-spring commented 1 year ago

It seems to be only/mostly relevant where there are overhead wires, so the quest could be limited to level crossings of railways with electrified=contact_line

westnordost commented 1 year ago

So, I guess it makes sense to ask for railway crossings with electrified contact lines.

rhhsm commented 1 year ago

I assume there is an international railway standard for the distance between rails and overhead wires? Then crossings with a height limit less than that standard should be very rare, and the quest would be very spammy?

matkoniecz commented 1 year ago

So, I guess it makes sense to ask for railway crossings with electrified contact lines.

Not everywhere. In Poland it seems that catenary height is higher than highest standard vehicle size and therefore height limit are unsigned.

gdprdatasubect commented 1 year ago

I assume there is an international railway standard for the distance between rails and overhead wires?

No there is not, have a look at that overpass-query I posted. Sometimes it varies even for a single country, for example India opened a line with a wire height of more than 7 meters to be able to double stack containers.

There are even different catenary-wire-widths, e.g. any locomotive that wants to drive on Swiss rails needs another set of Panthographs

westnordost commented 1 year ago

Anyway, I do not think it is worth the effort to research in which countries a certain always-sufficient min height for electrified contact lines can be assumed, considering that such railway crossings are not that frequent that it would feel like spam to be asked maybe a little too often. From my side, it can be implemented as described: For all railway crossings that share a node with a railway line that has an electrified contact line.

The code is here in case anyone would like to create a PR:

https://github.com/streetcomplete/StreetComplete/blob/master/app/src/main/java/de/westnordost/streetcomplete/quests/max_height/AddMaxHeight.kt

It would make sense to add a unit test for this case, too. Current tests for this quest are here:

https://github.com/streetcomplete/StreetComplete/blob/master/app/src/test/java/de/westnordost/streetcomplete/quests/max_height/AddMaxHeightTest.kt

westnordost commented 1 year ago

@gdprdatasubect it would be useful if you uploaded the first photo you got there (if it is yours) also into the wiki to be mentioned in https://wiki.openstreetmap.org/wiki/Key:maxheight

gdprdatasubect commented 1 year ago

(if it is yours)

Unfortunately not, but i'll ask the photographer and check a local railway crossing if he says no.

FloEdelmann commented 1 year ago

FYI: Related question about this issue in the OSM Forum: https://community.openstreetmap.org/t/streetcomplete-fragt-bei-eisenbahn-weg-kreuzung-nach-durchfahrtshohe/103606/27

claudiush commented 1 year ago

The problem with this quest is that in cities with tram infrastructure (e.g. my experience in Leipzig) suddenly the whole city is plastered with these quests and it took me a few days to understand this wasn't triggered by a bug with the generic maxheight quest, but because the crossing tram lines have overhead wires. I don't know of a single crossing in Leipzig that has the maxheight signed for any tram crossing, so there seems to be very little value. Maybe ignore the quest for railway=tram ?

westnordost commented 1 year ago

It seems to be a useful information whether the maximum height on roads is limited due to the tram overhead wires, as these wires are not particularly high up. Then again, if such information is virtually never signed for trams, it indeed would make no sense in asking for it. Would need some input, how is it in other places with tram lines - or maybe the signs come earlier, not directly in front of the crossing?

matkoniecz commented 1 year ago

I have never ever seen such signs for tram crossings in Poland (though I have seen trams only in few cities...). Also, in Poland it is extremely, extremely rare also for rail level crossings.

mnalis commented 1 year ago

Never seen in it on tram crossings in Croatia, very rare for rail level crossing too.

westnordost commented 1 year ago

Alright, I excluded tram lines