OpenStreetMap
‘Le Passage du Gois’ is mostly under water. During spring tide it can be used from 1:45 before to 1:45 after ebb. At neap tide or bad weather, the recommendenation is only to cross exactly at ebb.
IMO, it is more a touristic attraction than a serious road.
How should this be designated? Tertiary road sounds too important and will draw navigation systems towards it (could be dangerous at night, as there is no barrier, just warning signs).
讨论
spark 于 2012年08月21日 20:32 的评论
I tagged this way as causeway=yes, tidal=yes. At the time, I couldn’t find any established system for tagging these types of roads.
Zverik 于 2012年08月22日 06:54 的评论
ford=yes probably
Vincent de Phily 于 2012年08月22日 09:41 的评论
Definitely ford=yes and tidal=yes. The former is usually shown on maps and probably avoided by most router configs.
I’m tempted by some access tag, but usual time-based ones won’t do. There’s one use of access:tide=yes in taginfo but it doesn’t make much sense to me. access:high_tide=no or access:tide= sound better. You could always add an access=limited or access=tidal; most routing engines will not know what to do with the value, and simply avoid the road.
As for your actual question of the highway= value, just tag as if it weren’t tidal (the other tags already defined that). From the look of it and the tagging guidelines for France, I’d go with tertiary.
Oh… and this is not a waterway (as currently tagged). Waterways are for boats and such.
chillly 于 2012年08月22日 11:26 的评论
A ford is something you can drive or wade through - the water only covers the road by a few cms. If the road is impassible yet it is marked as a ford this is badly misleading.
Vincent de Phily 于 2012年08月22日 14:32 的评论
By your description, this road is indeed a ford, if only for a few hours each day. Even fords on rivers depend on the amount of water currently present (some riverbeds go from completely dry to flood-like during the season or because of a dam). The timescale is different but it’s the same issue. What counts as “passable” also depends a lot on your vehicle.
All in all there’s no hard rule, but if you can cross it under some circumstances, I’d say it’s a ford.
jutezak 于 2012年08月22日 19:28 的评论
Well, with flood it has a few meters of water, so the only vehicle applicable will be a boat ;)
I’m going for ford=yes, access=tidal, and downgrade it to highway=unclassified. The downgrade because it is not really for normal traffic; there is a much better bridge nearby that is not slippery and a lot wider.
Causeway does not seem to be the right tag; that seems to be a road on a kind of dyke or a road on poles like a low bridge that is too low to pass under, like the road connecting Venice to the mainland.
marscot 于 2012年08月24日 13:38 的评论
I have drove on this road its a tidal causeway. causeway=yes, access=tidal, lit=no highway=unclassified, but highway=track + tracktype=grade1 maybe be the best way to tag the road type.
jutezak 于 2012年08月24日 15:29 的评论
Hmmm… as highway=track it renders dotted. Changed it anyway. Maybe someone can chime in whether this road is actually useful for non-local car traffic (I doubt it).
I also note that the road is tagged psv=yes. That seems to mean ‘to ordinary traffic can pass here’ - which does not seem true.
marscot 于 2012年08月24日 16:39 的评论
here is a link to see theTour de France Crossing the road that day I was there.