Hi Joe and Andrew, thanks again for the feedback. Andrew's post raised lots of points which need to be addressed separately, but can I test your patience by focusing on a key issue that was raised, which is how to interpret access conditions on tracks that do not have an access tag. Namely, these two comments:
JG: "I'd suggest the problem is with routers assuming that a missing access tag should be interpreted as access=yes. If a common understanding was reached that a missing access tag on a highway=track is *assumed* to imply access=no until proven otherwise, then it seems the problem goes away?" AH: "no access tags don't mean access=yes (public) it just means access hasn't been set. " Joe, when you talk about reaching consensus, I assume you mean consensus among the Australian osm community, not the global osm community. Is that right? The highway=track wiki states: "highway=track does not imply any particular access=* value", and different countries have adopted different positions on the issue, as described here (thanks for the link Andrew): https://wiki.openstreetmap.org/wiki/OSM_tags_for_routing/Access_restrictions In most countries that have reached consensus, the absence of an access tag on tracks is implicitly taken to mean that access=yes for motorcars. This includes Austria, Belarus, France, Finland, Italy, Netherlands, Spain, Switzerland and the Ukraine. (Brazil, Germany, Iceland and Belgium have partial/proposal variations on a yes approach). In contrast, two countries went with access=no (Finland and Denmark). Many countries haven't reached consensus, including Australia. Have I interpreted this correctly? This message isn't meant to be part of any process for reaching a consensus in Australia. That discussion needs to be approached far more deliberately and inclusively. I'm trying to understand whether, to some degree, Andrew and I have been talking past each other because we have different views on this fundamental issue. About 92% of tracks in Australia do not have an access tag (TagInfo Australia), about 5% have access=private, 1% have yes and 1% have no. If I understand things correctly (and this is the whole point of this email), this means that: - Strictly speaking, since no consensus has been reached in Australia, 1% of tracks are known to be open to the public, 1% are known to be closed, and access is considered to be unknown on 92% of mapped tracks. - If the community accepted a default position of access=no (i.e. all tracks without an access tag are implicitly assumed to be closed to public vehicles), 1% of tracks are known to be open to the public, 1% are known to be closed, and access is assumed to be closed on 92% of mapped tracks. - If the community accepted a default position of access=yes (i.e. all tracks without an access tag are implicitly assumed to be open to public vehicles), 1% are known to be closed to the public, 1% are known to be open, and access is assumed to be open on 92% of mapped tracks. Have I got this right? If I have, then would this lead to the following implications for tagging decisions? - Under the current position of no consensus, a "maximilist" tagging approach is required, and it's equally important to add access tags to all tracks, whether open or closed on the ground. - If the community accepted a default position of access=no (i.e. all tracks without an access tag are implicitly assumed to be closed to public vehicles), then it's most important to add access tags to all tracks that we know are open on the ground (with evidence of course). It's less of a priority (but still useful) to add tags on tracks where access is known to be no/private/etc. - If the community accepted a default position of access=yes, then it's most important to add access tags to all the tracks that we know are closed/restricted on the ground. It's less of a priority (but still useful) to add tags on tracks where access is known to be open. - Alternatively, as Andrew suggested, some editors may prefer to adopt the maximilist approach (tag 'em all) regardless of what decisions we adopt, because many data consumers (routers etc) may not be aware of, or have the capacity or interest in basing their products on our consensus. Thank you all for your tolerance, I'm keen to make sure I haven't misunderstood any of these principles and their implications. Best wishes Ian
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