I should start by saying I’m fairly new to all of this and the learning cliff is pretty extreme but I think I’m starting to get my head round things. I’ve been using the garmin.osm.nl “generic new” maps as one of my map sets since I replaced my original GPS with a newer one after the GPS week roll-over.
I’ve been doing a bit of OSM editing in my area, but some things aren’t – or aren’t entirely – OSM data errors. The first thing I’ve dug deep enough that it looks like a style issue is that an area round where I live appears in the garmin.osm maps as “Nature Reserve”, e.g., at N55.93251° W3.17980°. It’s not a nature reserve.
This appears to be the rendering of this feature, which is a designated local cultural conservation area with restrictions on building types.
I think I have two problems here. The first is that it’s a boundary=protected_area (correct) but that the original editor has set its subtype to protection_class=22 to indicate the kind of protected area. I think I’m right in saying that should actually be protect_class=22
It would be interesting to know if anyone agrees that’s mistagged; obviously I can go in and fix it if so. It actually seems to be a common error in this city, with 25 occurrences in the .osm file, probably all by the same mapper.
However, I think that the current style would still render this area incorrectly because the polygons file says:
leisure=nature_reserve | boundary=protected_area | boundary=nature_reserve [0x16 resolution 20 continue]
There’s no attention being paid to the value of protect_class (and even less so protection_class!) and in fact the only reference I can find to protect_class is also in polygons, like this:
boundary = national_park & protect_class > 2 {set boundary=nature_reserve}
boundary = national_park [0x16 resolution 18 continue]
In other words, any “protected area” ends up being a type 0x16 polygon, which is defined in the TYP file as follows:
[_polygon]
Type=0x16
String1=0x04,Nature reserve
So apart from the mistagging issue (if I’m right about that) I think the style would also need to be modified something like the following:
leisure=nature_reserve | (boundary=protected_area & protect_class<=2) | boundary=nature_reserve [0x16 resolution 20 continue]
That’s not a real proposal, though, because the values of protect_class are really complicated. I wouldn’t want to propose something that accidentally hid a lot of real nature reserves…
Sorry about the long explanation. It’s mainly there because, as I say, I’m pretty new to this so I’m not sure which conclusions are correct and which are not. Over to the experts!