Hi blc, maybe the misunderstanding is on my side. I've implemented the support for via-ways in 2014 [1]. For such a no_* restriction there is no way to express the same situation with via-nodes. The Garmin IMG format only knows restrictions which forbid to follow a certain list of nodes in a given order. So, I tend to interpret OSM restrictions like that and for an OSM "no" restriction this works fine. I searched the tagging list and found http://gis.19327.n8.nabble.com/mandatory-restriction-with-via-way-as-members... Following this thread the relation 2155309 means: If you are on "from" way 223720277 you must use the "via" way followed by the "to" way. I fear this is currently not implemented in mkgmap, it more or less translates the relation into a no_u_turn restriction with way 161220789 as "to" way and thus allows a right turn from way 172716357 via node 1732097310 to way 161220701. IIGTR the code in mkgmap should be changed to add more restrictions in the IMG data... Gerd ________________________________________ Von: mkgmap-dev <mkgmap-dev-bounces@lists.mkgmap.org.uk> im Auftrag von blc <blc@mail.vanade.com> Gesendet: Dienstag, 8. Oktober 2019 06:05 An: Development list for mkgmap Betreff: Re: [mkgmap-dev] Turn Restrictions using three ways - design guide for OSM mappers? Still having a bit of misunderstanding, I think. Maybe take a look at relation 2155309 which also triggers the warning. https://www.openstreetmap.org/relation/2155309 Here there appears to be no other relations describing this turn other than the one more that prohibits left turns on the right turn ramp which is only tangentally related. My take is that the mapper decided to write it this way for some reason, perhaps there's a sign that says such, I don't know. While this too can be written as two TRs: - one to prohibit right turns - one to prohibit U-turns. iD even seems to understand this way-as-via does both with just one restriction relation, you can click and mouse over the voodoo doll sidebar and it seems to understand the original mapper's intent. In fact I think you can make iD can create way-as-via only relations. So what should a mapper have done here from the get go? Should they have omitted it completely? What about a QA fixer? Or should these warnings simply be ignored -- there are hundreds of them in the USA. Thanks, and sorry for any misunderstandings. On Sat, 5 Oct 2019, Gerd Petermann wrote:
Date: Sat, 5 Oct 2019 14:31:29 +0000 From: Gerd Petermann <gpetermann_muenchen@hotmail.com> Reply-To: Development list for mkgmap <mkgmap-dev@lists.mkgmap.org.uk> To: Development list for mkgmap <mkgmap-dev@lists.mkgmap.org.uk> Subject: Re: [mkgmap-dev] Turn Restrictions using three ways - design guide for OSM mappers?
Hi blc,
I meant the relation 2256354 is obsolete, wrong, or meaningless, whatever you want to call it. I can't think of any situation in which a only-* restriction with a via way makes sense. Can you give one? What would be restricted by such a restriction?
Gerd
________________________________________ Von: mkgmap-dev <mkgmap-dev-bounces@lists.mkgmap.org.uk> im Auftrag von blc <blc@mail.vanade.com> Gesendet: Samstag, 5. Oktober 2019 16:12 An: Development list for mkgmap Betreff: Re: [mkgmap-dev] Turn Restrictions using three ways - design guide for OSM mappers?
Gerd,
Ahhh... Now I understand what you mean. I think you initially mean "redundant" versus "obsolete" - I was confused by "obsolete" thinking that the restriction should use a different method due to an outdated methodology.
For the example, turn restriction 3843893 was the one that made the initial turn restriction 2256354 redundant. If 3843893 had not been there, what would the suggestion be?
I'd suspect that relation 3843894 is still needed regardless as the startpoint is different.
Thanks
On Sat, 5 Oct 2019, Gerd Petermann wrote:
Date: Sat, 5 Oct 2019 13:31:09 +0000 From: Gerd Petermann <gpetermann_muenchen@hotmail.com> Reply-To: Development list for mkgmap <mkgmap-dev@lists.mkgmap.org.uk> To: Development list for mkgmap <mkgmap-dev@lists.mkgmap.org.uk> Subject: Re: [mkgmap-dev] Turn Restrictions using three ways - design guide for OSM mappers?
Hi blc,
there are already normal restrictions [1] which look correct to me, so as I said before this one is obsolete. I think it should be removed. Besides that I would not add restrictions without local knowledge or other allowed sources.
Gerd [1] https://www.openstreetmap.org/relation/3843893 https://www.openstreetmap.org/relation/3843894
________________________________________ Von: mkgmap-dev <mkgmap-dev-bounces@lists.mkgmap.org.uk> im Auftrag von blc <blc@mail.vanade.com> Gesendet: Samstag, 5. Oktober 2019 08:53 An: Development list for mkgmap Betreff: Re: [mkgmap-dev] Turn Restrictions using three ways - design guide for OSM mappers?
Gerd,
Thanks for the reply.
So it looks like it's still being handled, but would you say that these should be changed in OSM?
It seems a bit strange that if you're on way A, you must travel through way B and get to way C, but indeed it is true that if you weren't allowed to make any turn at the point between A and B (and B and C), you'd get the same result -- is this the prefered way of denoting such?
For this particular example in OSM I suspect the mapper did not want to allow right turns at the intersection (even if it's not illegal) and hence wrote the restriction as an only left way-way-way instead of a way-point-way no right turn, perhaps because of either a sign or the paintings on the road and you can't make an "only left turn" on the first intersection of the dual carriageway because that's the wrong direction.
How should this particular intersection be restricted from travel to not emit warnings? Adding that no right turn at the first intersection would probably have the effect, but I've seen a lot of these way-way-ways around (mostly dealing with complex dual carriageway intersections between multiple roads) and wonder if it's worth "fixing" them, or should these warnings be simply ignored for the most part?
Thanks!
On Sat, 5 Oct 2019, Gerd Petermann wrote:
Date: Sat, 5 Oct 2019 05:43:56 +0000 From: Gerd Petermann <gpetermann_muenchen@hotmail.com> Reply-To: Development list for mkgmap <mkgmap-dev@lists.mkgmap.org.uk> To: "mkgmap-dev@lists.mkgmap.org.uk" <mkgmap-dev@lists.mkgmap.org.uk> Subject: Re: [mkgmap-dev] Turn Restrictions using three ways - design guide for OSM mappers?
Hi blc,
the code that produces these warnings is this: if (valid && !viaWays.isEmpty() && restriction.startsWith("only")){ log.warn(messagePrefix, "check: 'via' way(s) are used in",restriction,"restriction"); }
So, mkgmap considers them valid, but dubious. I think that's what they are. The restriction says something like "when you want to travel from way A via way B to way C you MUST travel from A via B to C" What kind of restriction is that? In my eyes, the given example is completely obsolete. On the other hand, a "no-" restriction with via way(s) means It is not allowed to go from A to C via B. This cannot be expressed with a single via node.
Hope that helps?
Gerd
________________________________________ Von: mkgmap-dev <mkgmap-dev-bounces@lists.mkgmap.org.uk> im Auftrag von blc <blc+mkgmap@mail.vanade.com> Gesendet: Samstag, 5. Oktober 2019 06:31 An: mkgmap-dev@lists.mkgmap.org.uk Betreff: [mkgmap-dev] Turn Restrictions using three ways - design guide for OSM mappers?
Hello, I thank all who have been working on this neat program to allow our otherwise old Garmins sit in the dust heap when we can't afford to subscribe to new maps.
I've been trying to improve the quality of OSM by fixing the errors that mkgmap emits, which a lot of times mirrors what's seen in KeepRight. However there's one variant of turn restriction I've noticed that warns in mkgmap but do not show up in KeepRight (and iD seems to understand this type of turn restriction) - the way-way-way type restriction where three connected ways are in series for non no-u-turn restrictions.
example:
Turn restriction (only_left_turn) 2256354 (at https://www.openstreetmap.org/?mlat=47.777585&mlon=-122.319488&zoom=17) check: 'via' way(s) are used in only_left_turn restriction
The way-way-way type is the proper method for restricting u-turns on dual carriageway roads which is understood by mkgmap. On the other hand, iD and KeepRight it seems to be valid to do way-way-way instead of way-POINT-way for no/only left/right turn restrictions, no/only straight on restrictions, etc. I've seen a lot of the non no-u-turn way-way-way restrictions in the USA.
These type of non no-u-turn restrictions seems to cause a warning in mkgmap and probably not translating them. My question is that should these be supported in mkgmap, or should these be fixed in OSM so that they are simple way-via-way despite iD and KeepRight seem to claim them valid? Or perhaps way-way-way is deprecated but still supported by OSM but should be changed to way-point-way?
way-point-way = relation from: some-street-way via: some-intersection-point to: some-street-way (this is the most common type of turn restriction)
way-way-way = relation from: some-street-way via: some-street-way to: some-street-way (this is necessary specifically for dual carriageway u-turn restriction, but it's used for other types as well which mkgmap complains about.)
Thanks for shedding some light on the discrepancy here! Note: I'm currently depending on OpenMapChest data for mkgmap runs as my computer and internet connection are not large or fast enough for the quantity of data I'd like to work with. _______________________________________________ mkgmap-dev mailing list mkgmap-dev@lists.mkgmap.org.uk http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev _______________________________________________ mkgmap-dev mailing list mkgmap-dev@lists.mkgmap.org.uk http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev
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