Yeah, I hadn’t seen the github issue. I’ll reply to it to keep the discussion in one place.
Good example near Kiel where there’s a grade3 track, although IMHO a ‘Betonspurplatten’ should be a grade1.. On 6 janv. 2015, at 12:51, Peter <[email protected]> wrote: > Hi Laurent, > > thanks for your analysis, very appreciated! Also the knowledge in > different countries is nice to have :) > > I can remember we excluded those tracks as it was very unusual in most > countries with grade > 1. So yes, if this is required then it is very > important to include grade2 and even 3 (I'm not sure if higher), maybe > we make this configurable in the CarFlagEncoder and per default it is 2? > Later we make this country-specific (#175) > > (BTW: The only downside will be that more streets are added to the > network and algorithms without CH will be slightly slower for long routes) > > Also I found this related issue (not yet looked again into it :)): > https://github.com/graphhopper/graphhopper/issues/253 > > Regards, > Peter > > > On 06.01.2015 12:40, Laurent Bendel wrote: >> OK, the code is actually pretty readable, I did my homework. It turns out >> the algorithm turns down tracks with tracktype=grade > 1. From >> CarFlagEncoder.acceptWay: >> >> if (tt != null && !tt.equals("grade1")) >> return 0; >> >> by changing this to >> >> if (tt != null && !tt.equals("grade1") && !tt.equals("grade2")) >> return 0; >> >> I get correct results, and given the very low weight given to such tracks, >> it shouldn’t impact much other routings. Or would it ? >> >> According to http://wiki.openstreetmap.org/wiki/Key:tracktype, grade2 should >> definitely be acceptable for a general purpose vehicle, grade3 probably too. >> As for the example outlined below (no man’s land between Mauritania and >> Morocco), it’s actually more like a grade4, mostly compacted sand, some soft >> sand. Still crossed by all kind of small cars every day. So if somebody >> corrects OSM with the more correct grade type, the routing will again fail. >> But this is unavoidable in the grand scheme of things. >> >> Any thought ? submit a patch ? >> >> Laurent >> >> PS: note that in Australia, some tracks are labeled highway=secondary or >> even highway=primary, so the problem doesn’t exist. >> >> On 5 janv. 2015, at 19:34, Laurent Bendel <[email protected]> wrote: >> >>> Hi there, >>> I’m new to graph hopper, but I’ve already spotted a problem: it seems the >>> algorithm decides that tracks (highway=track) are impassable by cars, but >>> OK for bikes. E.g.: >>> >>> https://graphhopper.com/maps/?point=Dakhla%20الداخلة%2C%20Morocco&point=Nouadhibou%2C%20Mauritania&layer=MapQuest >>> >>> The problem is, in quite a few countries outside of Europe, main roads can >>> be so bad that they are classified as tracks, but still used by thousands >>> of normal cars, buses and lorries. The border between Mauritania and >>> Morocco is a typical example, it is actually the only link between North >>> and West Africa..! Maybe they should be weighted « less » than >>> highway=unclassified, but still taken in account. Any reason it is >>> implemented this way ? >>> >>> I’m using the graphhopper.com service, not my own server. >>> >>> Thanks, >>> Laurent >>> >>> >> >> _______________________________________________ >> GraphHopper mailing list >> [email protected] >> https://lists.openstreetmap.org/listinfo/graphhopper > > > _______________________________________________ > GraphHopper mailing list > [email protected] > https://lists.openstreetmap.org/listinfo/graphhopper _______________________________________________ GraphHopper mailing list [email protected] https://lists.openstreetmap.org/listinfo/graphhopper
