If you want a routing app to navigate you along an OSM route (using gpx as intermediate), or a comparable dat use of OSM routes, the route must be ordered correctly or it simply won't work. If 65% of the routes is ordered, that means 35% is not and you can't rely on it for routing or profiling. I would say you need at least 95% correct.
Vr gr Peter Elderson Op vr 3 mei 2019 om 18:39 schreef Sarah Hoffmann <lon...@denofr.de>: > Hi, > > On Fri, May 03, 2019 at 01:24:49PM +0100, Andy Townsend wrote: > > Seriously, hoever wrote that section of that wiki page > https://wiki.openstreetmap.org/w/index.php?title=Relation:route&action=history > > must have done so out of their _desire_ that relations are kept ordered > in > > OSM, not out of any observation that they actually _are_ ordered. > > I haven't edited the wiki page but I'm likely responsible that it > appeared because of this post: > https://www.openstreetmap.org/user/lonvia/diary/42262 > > Please note the statistics at the end of the post. I actually > did bother to observe the state of affairs and I found that a > majority of routes in fact _are_ already sorted. The numbers > are from before waymarkedtrails stopped sorting routes, i.e. > they are not distored by the fact that people wanted to see > a clean elevation profile on the site. > > > In OSM you need to deal with the data as it is, not as you'd like it to > be - > > the nature of the project, where anyone can contribute, and they may not > be > > even aware of concepts that you care deeply about makes it fundamentally > the > > worst place to be an architecture astronaut (as per > https://www.joelonsoftware.com/2001/04/21/dont-let-architecture-astronauts-scare-you/ > > etc.). > > This judgement is a bit unfair unless you have actually tried to > sort routes. It's easy for the 2/3 or so routes that are strictly > linear. For everything else, it's hard. It's essentially an optimisation > problem. And no matter what you do, part of your algorithm involves > guessing what the mapper might have wanted. That is the point where > I argue that the mapping is flawed and might miss some information > that the mapper actual has at their disposal. > > Here is an example of a route that is really hard to sort > automaticaly but is perfectly usable when used in the order it > appears in the relation: > https://hiking.waymarkedtrails.org/#route?id=1115137 > > > That's not to say that we can't try and make contributions better, but > the > > way to do that is to modify the tools that people use to contribute to > OSM > > not to write wiki pages that no-one reads before they start editing. > > As everything in OSM, you don't need to read that wiki page and you > have the freedom to sort your routes or not. If you don't want to > bother, that's perfectly fine. An unsorted route is not wrong, it's > only less precise. Maps can show it without issues including > waymarkedtrails. It just can't give you some advanced features. > > One more point: > Most editors are quite good at keeping route order these days (iD has > looong ago been fixed). But even when they get it wrong (mostly due to > complicated way splits or reversals) having routes sorted actually > means that the damage is less severe because when you stitch the > remaining parts together, the result is still very usable. > > Kind regards > > Sarah > > > _______________________________________________ > Tagging mailing list > Tagging@openstreetmap.org > https://lists.openstreetmap.org/listinfo/tagging >
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