Uncorrect routing information generated by OSM restrictions
  • Hello,

    I'm a OSM conbtributor - often editing maps on openstreetmap.org. It seems that the Android version makes errors with the turn restrictions of Open Street Map (OSM ).

    You can add different turn restrictions:

    • only_right_turn
    • only_left_turn
    • only_straight_on
    • no_left_turn
    • no_right_turn
    • no_straight_on
    • no_u_turn

    If you add a "only_" restriction to from road a to road b this means that you can only turn from a to b and not to any other direction from a.

    If you add a "no_" restriction to from road a ro road b this means that you can't turn from road a to road b but to any other direction.

    The "no_" restrictions are interpreted right by MapFactor. But "only_" restrictions are not. They are interpreted as if they were "no_" restrictions. For example you are only allowed to turn right from road a to road b but not to turn left to road c. In OSM this would be "only_right_turn from a to b". MapFactor does not understand it and routes you from a to c what is not allowed. It seems that MapFactor does not differenciate between "only_" and "no_" restrictions. It interprets all as "no_" restrictions.

  • 5 Comments sorted by
  • Hi MP1902,
    can you please give me some relation ID or coordinate where you are sure it is correctly mapped but wrongly interpreted? I will double check it on your example.

  • Hello,

    yes, I can provide you the information.

    It happens at node 59348112 (coordinates E12.88155, N50.85384). At this node the roads 139376184, 37287816 and 7955058 meets.

    There is a "only_straight_on" from road 139376184 to road 37287816. But MapFactor free navigates you from road 139376184 to road 7955058, which is forbidden (and very dangerous).

    You can reproduce this by navigating from "Hartmannstra├če, Chemnitz, Saxony, Germany" to "Leipzig, Saxony, Germany".
  • There is something wrong indeed. If I route (option shortest) with pc navigator just behind this intersection, routing is going out of town and via autobahn back to this point (10 km). If I route just before this intersection, route is only 3.2 km on what one would exspect to be the shortest route.

  • @MP1902, do you mean http://www.openstreetmap.org/browse/relation/2470970? I check that in germany_osm_east, data creation=201211160 and routes as expected. Also note, that there was some edit recently, ... so which relation do you mean? This is from Thu, 11 Oct 2012 23:45:05 ...
    p.s. do you have "Car" profile? (restrictions do not work for bike/pedestrian)
  • Yes, seems really to be a map problem (but already a solved one). I installed the latest maps and the problems have gone. So it's proven that MapFactor handles the restrictions in the right way. It was an already fixed problem in the map, but was not in the latest maps downloads.

    Everything fine now. Thanks to everybody for your help!

Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!

In this Discussion