On Wed, 2014-01-01 at 22:57 -0200, Fernando Trebien wrote: > Welcome, David. If you've just been advised about this discussion, you > may wish to read it from the start: > http://gis.19327.n5.nabble.com/Tags-useful-for-rendering-of-roads-in-poor-conditions-td5791303.html > Actually, the particular issue has been on the table for five years ! Please see https://trac.openstreetmap.org/ticket/1447 We did not get anywhere in the life of mapnik ....
> .... classifying roads as highway=track simply > because they are unpaved Yep, thats a bad thing. Its important that the highway= tag is not intended to address the state or condition, its meant to describe what the road is intended for. But the special case of highway=track messes that up ! There is no reason to assume tracktype= applies only when highway=track. An unfortunate semantic link, thats all. > I'll try to summarise: I'm pretty much open to using either the > surface or the tracktype tag, Agree. What is important is that we come up with one recommendation so people know what to put into OSM and renderers have a reasonable understanding of it. Tracktype= outnumbers surface=unpaved 2:1 in the database. But there are a lot of other surface= values. In some cases surface= values are subsets of other values and sometimes they are mutually exclusive. So people are sometimes unsure what to use. So in the Aus guidelines, we encourage people to just use surface=unpaved. We also advocate use of the 4wd_only= where necessary. > .... To make > tracktype popular with highways that are not highway=track, I believe > we'd need to request JOSM's developers to add a tracktype field to > many presets, so it's extra trouble. I think the JOSM developers are more likely to follow common usage. If enough people ask for that then the developers will implement it. But its quite easy to do in JOSM 'manually'. I routinely do so. > .... that tracktype=grade1 can > be considered "paved" (for rendering) and any other tracktypes can't. > But in the absence of that tag, we can then use the surface tag to > decide. That may be more complicated than needed IMHO. In practice, few if any rendering engines look at surface=. Lets leave it that way. If tracktype= is not asserted, we already assume its paved or similar. I guess my point is that to 'fix' the problem, all that needs to happen is the renderers observe tracktype whenever its there, not just when highway=track. >If I were mapping in Brazil, I'd certainly prefer "paved" as default, Agreed, thats far too much the default to dream of changing it. AlaskaDave said the same thing. Anyway, if we all agree to recommend "surface=" (rather than tracktype=) as the trigger for 'different' rendering, I would be willing to go along. Unhappy but willing. I guess all that would need to happen is we add a note to the surface= wiki page to say values listed under 'Unpaved' be shown differently. I would be a bit sad if we went that way as my dream of adding three extra grades to tracktype= would be a bit harder but at least the more common cases would be dealt with. And that is important. David _______________________________________________ Tagging mailing list [email protected] https://lists.openstreetmap.org/listinfo/tagging
