[talk-au] Aus tagging guidelines on highway surface tags

Sun Jan 31 11:07:18 UTC 2021

I would add that you should do this on 
a large screen, Overpass Turbo 
interface is not working well on mobile 
devices (and it likely waits for someone withboth ability to fix it and time and willingness to fix it)

31 Jan 2021, 11:28 by mapslittle at gmail.com:

> Thanks for your helpful feedback folks, I’ll add an sentence or 2 on using detailed surface tags rather than just paved vs unpaved and will update the guidelines this week. 
>
> If you’re interested in seeing the state of play across the nation, this overpass query shows paved, unpaved and untagged roads in different colours for each road hierarchy level (primary, secondary, etc). It’s a great way to see where the gaps are and how much fantastic work the OSM community has accomplished.
>
> http://overpass-turbo.eu/s/12Zg
>
> If you haven’t used overpass before, it’s super simple...
> Click on the link above and a map will open in your browser
> Press the run button in the top left corner and wait a bit
> You can turn the confusing circles off by pressing the Settings button at the top, then selecting the Map option and then putting a tick in the box that says, ‘Don’t display all features as POIs’ and pushing Save.
> You can hide the programming box on the left by pushing the left arrow button below the +/- symbols
> Then push Run again, and magic!
> You can move the map around to any part of the world.
> OSM is truly awesome :)
>
>
>> On 31 Jan 2021, at 5:35 pm, Bob Cameron <bob3bob3 at skymesh.com.au> wrote:
>>
>>   
>>
>>
>> Ian/all 
>>  
>>  I have been boldly marking paved and no-tag as asphalt,      causeways/fords/bridges as concrete (etc) as a result of examining      my own Mapillary imagery, sometimes dovetailing that with the DCS      data. These are not only regional highways, but backroads and most      of small towns. 
>>  
>>  I actually use the overpass query to help route plan, deliberately      checking those with no tag. The query also showed a number of      really strange errors, like only the ends of a rural road are      paved in real life, yet an entire road was paved (with a surface      tag) on OSM (West Wilcannia Rd from Menindee to Wilcannia for      example) 
>>  
>>  >> https://www.openstreetmap.org/changeset/98337907>>  
>>  
>>  My Garmin GPS unit with an OSM based map tries to route me down      unpaved roads too.. Good surface information will give credibility      to OSM map data for general navigating. 
>>  
>>  I'll admit I have concerns that my surface tags for a paved      highway might be removed, so I welcome the change. 
>>  
>>  Bob 
>>  
>>
>>
>> On 31/1/21 3:13 pm, Little Maps wrote:
>>
>>> Hi folks, wondering if I can promote some discussion about          the section of the Aus tagging guidelines on adding surface          tags on roads. The text currently reads,
>>>
>>> “For most types of highway=* tags you don't need to specify the        surface=paved key/value pair as this is assumed, however make        sure you tag the road surface when it isn't a paved road.”
>>>  
>>>  This assumption is fine in large cities but is problematic in        rural and regional Australia. Can I suggest that it is replaced        by something like the following...
>>>  
>>>  "Surface tags should be added to roads wherever possible,        especially in regional areas. This advice differs from that on        the international key:surface wiki page, which states that,        'there is normally an assumption that the surface is        surface=paved unless otherwise stated.' However this assumption        is not valid across regional Australia as: (1) most roads,        including many major roads, are unpaved, and (2) mapping        intensity varies greatly among regions. Many roads that do not        have a surface tag may not have been examined by mappers. Adding        a surface tag will assist data users and help mappers to further        refine the regional road network."
>>>  
>>>  Long rationale (not for posting on the oz tagging guidelines        page)...
>>>  
>>>  
>>> Surface tags have been added to relatively few rural roads          in many regions. Hence, the most prudent assumption is that          the absence of a surface tag means that the road surface has          not received attention from mappers. A default assumption that          any road without a surface tag is actually paved is most          likely wrong.
>>>
>>> Efficiency of mapping. Even if one has no interest in adding        tags to paved roads, the most efficient way to refine surface        tags is to interrogate untagged roads and tag them (e.g. by        using an overpass query that distinguishes untagged, paved and        unpaved roads, and variants thereof. Untagged roads can be        inspected and tagged as appropriate.) However, if mappers are        advised to not tag paved roads, then every paved road that is        untagged needs to be re-examined each time this is attempted.        This wastes a lot of effort.
>>>  
>>>  Some apps — especially routing and cycling apps (e.g. Osmand and        Komoot) — allow users to request paved or unpaved routes.        Regardless of the (unknown) assumptions that routers make about        road surfaces when creating routes, apps like Osmand present the        data back to users. The suggested route may be X% paved, Y%        unpaved and Z% unknown. In many regions, Unknown is the largest        category. This doesn’t inspire confidence in the route or        underlying data.
>>>  
>>>  Some assumptions about road surfaces can obviously be made. For        example, a primary road is more likely to be paved than an        unclassified road. However, most roads in rural areas are        tertiary or unclassified. Some are paved, many not; the ratio        varies unpredictably across regions and it is impossible to        predict which roads are paved unless they are tagged.
>>>  
>>>  Perhaps not surprisingly, the OSM wiki on key:surface gives        conflicting advice, beginning with the (European?) position that        “there is normally an assumption that the surface is        surface=paved unless otherwise stated” and later adding an        (American?) view that, “There are no default values for surface,        it is generally considered as OK and desirable to tag it        explicitly for all roads.” The latter approach seems most        appropriate in regional Australia.
>>>  
>>>  Adding surface tags to both paved and unpaved ways is the most        efficient method to: (1) allow data users to accurately predict        road conditions (this benefits users) and (2) improve the rate        at which unpaved roads can be reliably distinguished from paved        roads (this helps future mappers). They may be redundant on        motorways, trunk and primary roads, but these make up a tiny        proportion of roads in regional Australia and can all be coded        with a minimum of effort.
>>>  
>>>  Advising mappers to not add a meaningful tag would appear to be        counter to the goals of accurate tagging. Can we change our        advice to encourage mappers to add a surface tag wherever        possible?
>>>  
>>>  
>>> Thanks for your time, I'm keen to hear your thoughts. Best          wishes, Ian
>>>
>>>
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