Missing ways part 2
Sections of railway are dropped during processing by mkgmap. The cause of this is that the sections are tagged layer=-1 even though they are not in a tunnel. The question which arises in a situation like this is: is the tagging wrong, or should the behaviour of mkgmap be changed? At first sight it seemed simple to me. A railway which is neither on a bridge nor in a tunnel should be in the default layer (layer 0). Any crossing ways on a bridge or in a tunnel should have the layer set to 1 or -1 respectively, except for multi-level civil engineering works. However, the contrary case is put in various OSM mailing lists. If a railway is in a cutting and crossed by several bridges, it is simpler and it also makes sense to put the railway in layer -1 and leave the bridges in the default layer. In my opinion, tagging with layer=-1 in that particular case is not wrong, but tagging long stretches with layer=-1 would be wrong. Looking at r1445 in the mailing list, it was clearly the intention to hide underground railways. In light of that, I suggest that the mkgmap default style might be modified to test for !(tunnel=yes) instead of !(layer<0), for all four types of railway.
On Mon, Oct 18, 2010 at 06:20:03PM +0100, Adrian wrote:
In my opinion, tagging with layer=-1 in that particular case is not wrong, but tagging long stretches with layer=-1 would be wrong. Looking at r1445 in the mailing list, it was clearly the intention to hide underground railways. In light of that, I suggest that the mkgmap default style might be modified to test for !(tunnel=yes) instead of !(layer<0), for all four types of railway.
Good idea. Would you happen to have an idea how to tag (and in mkgmap) hide a highway=service tunnel for accessing a railway tunnel? Here is an example that I added some time ago: http://www.openstreetmap.org/browse/way/69679696 Last time I was bicycling/mapping there, I got confused, because I thought that there would be a connection between the highway=residential (Kaskelanpolku) and the highway=secondary (Lahdentie). Of course, the tunnel would not be considered for routing, because the ways share no nodes, but the ways seemed to be connected on the map display. Marko
Marko Mäkelä wrote:
Last time I was bicycling/mapping there, I got confused, because I thought that there would be a connection between the highway=residential (Kaskelanpolku) and the highway=secondary (Lahdentie). Of course, the tunnel would not be considered for routing, because the ways share no nodes, but the ways seemed to be connected on the map display.
Hi, maybe this rules before your highway-rules in lines-file would solve your problem: bridge=yes | bridge=true [0x28 resolution 21 continue] tunnel=yes | tunnel=true [0x27 resolution 21 continue] aighes -- View this message in context: http://gis.638310.n2.nabble.com/Missing-ways-part-2-tp5647895p5649892.html Sent from the Mkgmap Development mailing list archive at Nabble.com.
On Tue, Oct 19, 2010 at 12:51:59AM -0700, aighes wrote:
Last time I was bicycling/mapping there, I got confused, because I thought that there would be a connection between the highway=residential (Kaskelanpolku) and the highway=secondary (Lahdentie). Of course, the tunnel would not be considered for routing, because the ways share no nodes, but the ways seemed to be connected on the map display.
Hi, maybe this rules before your highway-rules in lines-file would solve your problem:
bridge=yes | bridge=true [0x28 resolution 21 continue] tunnel=yes | tunnel=true [0x27 resolution 21 continue]
We are talking about the mkgmap default style. In the default style, 0x27 and 0x28 are used for aeroways and pipelines. I would like to omit truly "useless" tunnels, not cover them with other lines. I guess I could try something along the lines of access=private & !(foot=yes) & !(bicycle=yes). Marko
Of course you'll have to change the ID's the style was just copyed from my style-file. Also you'll have to extend the rule, if you just want to have highway-tunnels. All in all I think, it is useful, to render a tunnel differnt than a normal street. aighes -- View this message in context: http://gis.638310.n2.nabble.com/Missing-ways-part-2-tp5647895p5650601.html Sent from the Mkgmap Development mailing list archive at Nabble.com.
On Tue, Oct 19, 2010 at 05:29:04AM -0700, aighes wrote:
All in all I think, it is useful, to render a tunnel differnt than a normal street.
Sure, it could be. On the Finnish OSM forum there was a recent discussion how to tag cycleway underpasses. The tunnel=yes tagged ways under highways sometimes are roads under bridges, and sometimes something that could be considered a tunnel (narrow walls) by a liberal definition of tunnel. "Real" tunnels are much longer than they are wide, aren't they? I would rather omit these "useless" tunnels from the map display, at least as long as one can't easily select which layers to display on the map. There are many access=private tunnels under cities that the general public is not aware of: wastewater treatment, access tunnels to railway tunnels, tunnels for emergency vehicles, you name it. It would be confusing to see them as ways on the map. That's why I hid the underground railways in the default style. Marko
participants (3)
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Adrian -
aighes -
Marko Mäkelä