[Tagging] surface=gravel problems

brad bradhaack at fastmail.com
Sat Apr 17 17:43:25 UTC 2021

On 4/17/21 12:24 AM, Robert Skedgell wrote:
> On 16/04/2021 22:15, Adam Franco wrote:
>> On Fri, Apr 16, 2021 at 2:46 AM Volker Schmidt <voschix at gmail.com 
>> <mailto:voschix at gmail.com>> wrote:
>>     I acknowledge there is a problem. I started out putting "gravel" on
>>     many maintained unpaved roads, only to look up the wiki some years
>>     later. I know use "fine_gravel" (taginfo 170k uses), which broadly
>>     corrisponds to the "gravel" of "gravel bikes".
>>     So, yes,  most of my "gravel" roads are really "fine_gravel", but I
>>     have no idea how widespread it is, and also how much it depends of
>>     the mapper's mother tongue.
>>     I would not redefine the value "gravel", rather put a warning on the
>>     page, pointing out that we have this wide spread confusion, and
>>     invite mappers to consider "fine_gravel".
>> I did the same thing -- tagged *many* roads with surface=gravel early 
>> on and since then have been using surface=compacted for graded and 
>> shaped roads made of fine gravel, surface=fine_gravel for roads where 
>> the fine gravel was just dumped and and spread around without a lot 
>> of roadbed preparation (many driveways and pedestrian walkways), and 
>> surface=unpaved everywhere else.
>> *Some larger-gravel examples:*
>> Just last week I was exploring some agricultural tracks and 
>> encountered some very large gravel that was quite challenging to ride 
>> on, not quite 13cm track ballast, but much bigger than most of the 
>> gravel used on roads, maybe 5-7cm. (images 
>> <https://www.mapillary.com/app/?lat=44.099519799959175&lng=-73.2845288&z=17&pKey=qmTlSH8QhKgJ9NK0u1QuKT&focus=photo>) 
>> I tagged this way <https://www.openstreetmap.org/way/19677175> as 
>> surface=gravel based on the wiki definition, but would like to 
>> characterize it differently from the other roads also tagged 
>> surface=gravel that use much finer stone.
>> I also recently surveyed this forest track 
>> <https://www.openstreetmap.org/way/362871403> that has even larger 
>> stones, a mixture from about 10cm-25cm. (images 
>> <https://www.mapillary.com/app/?lat=43.24208888888889&lng=-73.01363055555555&z=17&pKey=L1GR6ZtaCiysWNyjEyBVwn&focus=photo>) 
>> I tagged this track as surface=gravel.
>> *Paths forward:*
>> I think surface=gravel alone has far too much mixed-usage to 
>> definitively say anything other than the surface is made up of random 
>> stones that aren't individually laid.
>> (A) More surface values: surface=fine_gravel could be augmented with 
>> surface=medium_gravel and surface=large_gravel with guidelines 
>> suggesting size ranges.
>> (B) Additional tags: Keep using surface=gravel as the general 
>> category and supplement with gravel=fine, gravel=medium, or 
>> gravel=large or similar tagging scheme with size guidelines. Maybe 
>> add compacted=yes/no where appropriate.
> For surface=gravel where wheelchairs, bicycles and vehicles are a 
> consideration, might it be worth updating the wiki to suggest tagging 
> appropriate values of smoothness=* (with examples) to use in conjunction.
> It won't solve the problem, but it might in the shorter help routers 
> which understand smoothness=*
Surface and smoothness combined describe the road pretty well.

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