Route cannot be computed Hiking/Walking

Lux Calor shared this problem 9 months ago
Closed

Have "route cannot be computed" message popping up quite often while setting up Hiking/Walking Navigation over established hiking routes.


I usually set it up from my current location to some point on map located on the route or in the next settlement.


The same happens while creating a route in the Route planner. See screenshots.


The difference is that in Route planner I can undo last step and try to place a point once more and sometimes it works. But the Navigation just refuses to compute the route even if I add intermediate points.


This happens on both LoMaps and OAM.


One interesting thing I have noticed is that in some problematic places there are few slightly different routes at the same time marking the same path in OSM. Maybe that is the reason.


With best regards.

Comments (17)

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If you are using BRouter in offline mode, it uses routing data downloaded by the BRouter app. If that data is outdated, the trail you see in LoMap and OAM may not correspond to what BRouter's data says is on the map. Make sure you use the BRouter app to downloaded the latest routing data for the map area you wish to use.

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I don't use BRouter currently. It is the default GraphHopper on and everything is online.


And this problem also happens in Route planner quite often.


Thanks for the tip, I'll keep this in mind when I do install Brouter.

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Tip: GraphHopper makes a distinction between "Walking" and "Hiking". If a trail crosses a stream marked as a "ford", the Hiking profile will route through it but not the Walking profile. This is not the cause of the problem you have encountered but it's useful to know in case you ever have GraphHopper refuse to route along a trail with one or more fords.

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Wow, thanks for the tip Taras. I tried both options on problematic areas, now will keep this in mind generally.


This app has a really nice community around it, I have to say! :)

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I have also tried this in latest beta and in different location on map. Still the same.


İn Route planner sometimes zooming in very close and positioning the next point very precisely on the trail helped in problematic areas. And sometimes it still did not.


But in some other areas pointing even on forest still beautifully created a route on nearby trail. I really hope this is intended behavior because it is very convenient. Especially while planning the route in a moving car.

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Hello Lux,

if you are using GraphHopper, are you able to simulate same problem on GraphHopper online map here https://graphhopper.com/maps/ ?

If so, you may post this issue directly on GraphHopper support forum https://discuss.graphhopper.com/ , or copy here url from mentioned map page and I'll post this issue there by myself.

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Hi Menion,


Yes, the behavior on GraphHopper maps is very similar. İt says "Connection between locations not found" often, but then suddenly works after I changed the finish point many times.


The map url is

https://graphhopper.com/maps/?point=36.779743%2C28.248805&point=36.795155%2C28.232441&locale=en-US&vehicle=foot&weighting=fastest&elevation=true&use_miles=false&layer=Omniscale


Are you using the GraphHopper engine for the route planner too?

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Thanks Lux,

then it's mean, that it is really some issue in GraphHopper. Locus use exactly same system that is used on this web page.

It is interesting, that just a small move or red pushpin compute route correctly, check this: https://graphhopper.com/maps/?point=36.779743%2C28.248805&point=36.795123%2C28.232476&locale=en-US&vehicle=foot&weighting=fastest&elevation=true&use_miles=false&layer=Omniscale and compare it to yours.

I'm not an OpenStreetMap expert, but one path has clearly defined parameters, second is missing some basic parameters like surface etc. https://www.openstreetmap.org/edit#map=19/36.79501/28.23294 , anyway it really needs someone more skilled, best someone directly on GraphHopper forum, so I post a question here: https://discuss.graphhopper.com/t/problem-with-routing/2664 and we will see.

Issue here may be anyway closed. Thanks

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Hi Menion,


Exactly. İn problematic areas sometimes zooming in very close and changing the point position for a millimeter helps. İt is the same way in Locus.


But generally route computing works outstanding in other places. Very happy with it.


So it is probably a location specific OSM/GraphHopper issue.


Thank you and all the best.

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I checked OpenStreetMap and there are mapping errors that prevent GraphHopper from finding a route between the two points you created.


There are two paths drawn very close together and they are not connected. My guess is there should only be one path and someone, for whatever reason, chose to draw a second path next to the first path. (???)


The first path was created 2 years ago. http://www.openstreetmap.org/way/278105881

278105881 is drawn correctly. It connects to the roads in Turunç and Içmeler.


The second path was created several months ago. http://www.openstreetmap.org/way/492814037

492814037 is drawn incorrectly. It does not connect to existing roads (or the first path).


In addition, the author drew the second path on *top* of the roads. Here's an example of what I mean:

http://www.openstreetmap.org/way/492814037#map=19/36.79592/28.23011


This second path is also part of an OSM relation called the KariaYolu and it is also drawn incorrectly (no connection to roads; drawn on top of them). http://www.openstreetmap.org/relation/7235931#map=17/36.76820/28.24922


All routing engines will have a problem finding a route involving the second path (492814037).

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Lux, please check topic on GraphHopper forum, where is message from GraphHopper developer.

https://discuss.graphhopper.com/t/problem-with-routing/2664

Hope this helps.

Menion

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Thank you, Menion


This same problem happens in few other places where the same editor added his tracks on top of the existing ones.


But all other places I tried are fine.


Anyway, this is an amazing dedication to your work sorting such details. Thank you again for that.


All the best!

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You are welcome.

If you discover more places with same (similar) problem, I really suggest to write about it to topic I started on GraphHopper forum. It may be a global problem that worth to solve on GraphHopper side.

Menion

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OpenStreetMap (OSM) is a created by volunteers. Anyone can add or modify data in OSM. The quality and accuracy of the work depends on the person's experience and attention to detail.


In this case, there's no polite way to say it other than the people who drew those trails did not know what they were doing. I've been editing OSM for over a year and this is the first time I've seen such mistakes.

Fortunately, they are not very difficult to fix. Unfortunately, the people who made them may not know how to fix them.

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You are right Taras,


That newer route is incorrect and also was not edited before posting to OSM, so it has those weird portions of GPS jumping when the guy took a break or something. But the KariaYolu marking is right. I am not yet familiar with OSM editing, so if you can remove this newer route somehow and mark the older one as KariaYolu that would be great. The older one is very accurate.


I would also really appreciate İf you can suggest some good resources on OSM editing.


Thank you.

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I normally only edit OpenStreetMap if I have good information about a particular area or I have personally visited it. I have neither for Turkey so I respectfully decline to make any modifications to KariaYolu.

KariaYolu might show the correct location of the trail but it has been improperly defined in OpenStreetMap. It does not connect to any road so it exists independently of everything else on the map.

There is no connection between Gölenye Caddesi (a road) and KariaYolu because the map-editor overlooked to connect them (he/she just drew the trail crossing the road but that doesn't automatically make them connected). As a result, a routing engine will be unable to route from Gölenye Caddesi to any point along KariaYolu.

When I examine the area using JOSM (powerful map-editing software for OpenStreetMap) it reports one error and many warnings. The error is the two paths drawn close together. One of the many warnings reports KariaYolu fails to connect to anything.

A Beginner's Guide to OSM mapping can be found here: http://wiki.openstreetmap.org/wiki/Main_Page

If you look at the information for the second path, it reveals the author: http://www.openstreetmap.org/way/492814037#map=15/36.7889/28.2396

Click the author's name and it will reveal his/her profile. You can contact the author (altay ozcan) and ask questions or request corrections for the second path. You need a (free) OpenStreetMap account to contact map-editors. There's no guarantee the author will respond.

Alternately, you can use OSM's Note function to create a note (containing corrections/suggestions) directly on the second path. Notes appear as red markers on the map (but only if you enable the display of Notes). With any luck, someone who is familiar with the area will read the note and fix the path. Notes can be created anonymously or using a free OSM account.

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Wow, thanks for a detailed answer Taras. Appreciated. And of course you are right in declining. I just didn't think of it from this perspective.

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