Circuitous route in Erfurt
  • Trying to navigate from "Pos@: 11.056676 50.972996" to "Pos@: 11.061509 50.972260" (OpenRouteService coordinates, I don't know how to link to an ORS route directly) on a fresh car profile using the free Android version (1.1.5) and the current testing maps, Navigator chooses an extremely circuitous route - it drives all the way around via Jenaer, Rudolstädter and Eisenberger Straße, instead of choosing the direct connection via Hermsdorfer Straße. I'm unable to discern a good reason for this in the OSM data. Moving either the start point beyond the traffic light ahead of it, or the end point ahead of the last crossroads, makes it select the correct route. Does anybody have any idea what's happening there?

    [edit] There's a turn restriction from the nearby sbt gas station to the right, so I thought it might be translating that into a one-way road, but it does the same thing if I swap start and end points. OSM error info does not seem to show any issues on the connecting road, but the big crossroads of Rudolstädter and Eisenberger does not have a maxspeed tag. Not sure if that's related.
  • 2 Comments sorted by
  • Hi,
    Hermsdorferstrasse is in category Other Small Rodas, which is switched off by default.
    You can switch this category on in settings/vehicle profiles/car/road restrictions

  • Ah, this does not seem to be correct (it's flagged as "highway=unclassified" in OSM, falsely imo).  I'll ask around what the correct setting for a well-maintained two-lane city asphalt road is. Thanks for the info.

    [edit] Okay, something is definitely going wrong here. #osm assures me that highway=unclassified should definitely not be considered unused by default. (This is a two-lane road connecting to the road network on both ends.)

    [edit] You're correct, enabling "small local road" in the settings made it work. What's considered a small local road? I'm not sure why those are off by default for a car - though it makes sense for a truck? There's a level of contradiction here, I think, where the program knows it has to eventually make its way onto the road, but tries to delay it as long as possible. I'm not sure that's appropriate behavior.

    [edit] Maybe the better solution would be to enable small local roads by default for cars, but give them a low priority? That'd avoid pathological behavior I've encountered, where the program takes huge detours to avoid spending even a second longer on a local road than necessary. For instance, in the example in my case, the program finds the right route even with priority as low as 15% (though it fails at 10%).

Howdy, Stranger!

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

In this Discussion