[talk-au] highway=track update

[Little Maps]

Thanks for the detailed history Michael!

As you say, most of the ways tagged ‘gravel’ in Australia could probably be re-tagged as ‘fine_gravel’ to more accurately follow the wiki and to accord broadly with common usage of the word gravel. 

Re compacted vs fine_gravel, personally I can’t tell the difference from the descriptions in the wiki. Both descriptions could be applied to the same stretches of rural road in many parts of Australia. Two problems are: the descriptions require mappers to know what is underneath the top surface layer and to know how the surface was made or applied (e.g. was it ‘rolled’ or not?). These aren’t mutually exclusive I’d have thought. Neither feature is common knowledge presumably, and both might be somewhat irrelevant if the road hasn’t been re-surfaced for a decade or so.

In an earlier message you said that you distinguished fine_gravel from compacted surfaces depending on whether the surface was loose (fine_gravel) or firm (compacted) when ridden on a bike. This seems to be a completely different distinction to that described in the wiki.  Wouldn’t this vary seasonally, and across the road surface from the edge to the middle, and over time, depending on how recent the road was maintained? 

It would be valuable to have a reliable distinction between earth/dirt/ground road surfaces (which may be bulldozed every so often but little more) from ‘improved’ compacted/fine_gravel/gravel surfaces, but distinctions beyond this seem unlikely to eventuate anytime soon. In the meantime, the numbers show that mappers prefer to use ‘gravel’ to indicate ‘improved’ road surfaces (i.e. compacted/fine_gravel etc), even though this usage contradicts the idiosyncratic definition in the wiki. The most obvious downside to this practice is that we don’t have a reliable way to distinguish the small number of road surfaces that are covered with coarse ‘railway ballast’ unfortunately.

If you’re interested, the taginfo data on surfaces in Australia is really interesting...

https://taginfo.geofabrik.de/australia-oceania/australia/keys/surface#values

Thanks again for your insights and for 16 years of great mapping!  Best wishes Ian


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