On Tue, Feb 26, 2019 at 3:23 PM Sergio Manzi <[email protected]> wrote: > And in Venice there is an official designation of roads accordingly to their > availability in case of exceptional high tides ("Acqua alta") of different > heights, but AFAIK this essential information is not registered anywhere in > OSM...
Even though it is not so comparable, in Brazil we have some places with really narrow public access paths that we decided to tag differently and we have so far liked the result (see [1] for an example). The criteria is simply if the way is wide enough for a car, if it's not then it gets downgraded to footway. This situation happens somewhat often in Venice too and it can be verified simply by measuring the distance between buildings using JOSM's measuring tool. For instance, I quickly found this street which is 1.5 m wide, too narrow for a car: https://www.openstreetmap.org/way/24990562 In some other cases, the measuring tool can also be used over imagery, such as to measure the widths of ways along channels, like this one, which is 1.8 m wide: https://www.openstreetmap.org/way/175023361 Also, wide ways that are only accessible through narrow streets would also be downgraded to footway, like this one: https://www.openstreetmap.org/way/216498689 The wiki says that highway=pedestrian [2] is meant for streets in which some vehicle traffic may be authorized. I don't think this is the case of most places in Venice (all my searches turned up that no vehicles, not even bicycles, are authorized there). The Italian translation of this article reflects this idea on the second paragraph. So I think that many highway=pedestrian in Venice are indeed incorrectly tagged and should be highway=footway. I would propose that highway=pedestrian is used there to represent the safe, wide paths used during acqua alta and that others that may be submerged (even wide ones that may still be tagged as highway=pedestrian) receive tidal=yes, even if the adoption if this idea is low [3][4]. Acqua alta is indeed more common in a season, so seasonal=yes/winter is a possibility as well. It would be nice to have highway=* with tidal=yes or seasonal=yes rendered differently, but there are no open tickets asking for that yet [5]. Of the four tags that may be used to indicate intermittently submerged highways (tidal=*, seasonal=*, intermittent=*, ford=*), only two are often combined with highway=* (ford=* and seasonal=*). As ford=* is for a different use case, I think it would make sense to request that seasonal=* highways get rendered differently. If all that makes sense and you do decide to classify Venice's streets differently, then I would recommend that the Italian wiki pages for highway=footway and highway=pedestrian contain a note about it, to avoid confusion among mappers. Also, link from those wiki pages to a forum thread discussing the topic in Italian, so as to help build consensus and for verifiability. Regards, [1] https://www.openstreetmap.org/?mlat=-30.10559&mlon=-51.24465#map=18/-30.10559/-51.24465 [2] https://wiki.openstreetmap.org/wiki/Tag:highway=pedestrian [3] https://wiki.openstreetmap.org/wiki/Proposed_features/Tidal_road [4] https://wiki.openstreetmap.org/wiki/Proposed_features/Tidal_path [5] https://github.com/gravitystorm/openstreetmap-carto/issues -- Fernando Trebien _______________________________________________ Tagging mailing list [email protected] https://lists.openstreetmap.org/listinfo/tagging
