"Measure distance / snap to road / walking" avoids direct routes in favour of terrible detours

[wandro]

Osmand+ 3.2.7 on Huawei Mediapad M3 with Android 7: "Measure distance / Snap to road / walking" avoids quite direct routes in many cases and suggests terrible detours. 

Example: The appended GPX track shows such a detour. It requires the offline map Germany/Hessen. Actvate the "Routes / Hiking symbol overlay".

Actually the waymarked trail "S2" should be selected, of course. 

Any workaround? (Note: In the settings I didn't define any routes to be avoided.)

[Nick A]

Hi,

There is a gate part way along the 'direct route' which has the tags;

barrier: lift_gate

bicycle:no

foot:no

which means any routing software for foot use will decide you can't go that way.  I don't know the area at all, so I'm unwilling to change the tags and it's too far away (love to go there one day though!)

Regards

Nick

(Tallguy)

[Nick A]

This links for details  https://www.openstreetmap.org/node/3111446446

[wandro]

Hi Nick,

many thanks for you enlightening hints. I'll try to contact the originator of that barrier tag. However, there seem to be many of those tags scattered all over the Odenwald mountains since we would frequently fail to compute distances and to plan hiking routes due tu such terrible detours suggested by the routing algorithm.

Regards,

Klaus.

[wandro]

Hi Nick,

how did you produce this informative view?

Is there a way to systematically search for a particular tag like "barrier" within a specific area?

Regards,

Klaus.

[Nick A]

Hi Klaus,

There are probably several ways of finding the barriers you would like to look at - this is my choice;

  1.Go to https://overpass-turbo.eu/ and scroll the map on the right side of the screen until it shows the area you would like to search (this will be the bounding box) - you can make it quite big so that it covers the whole area and gives all of the barriers you would like to search for.

  2. Click on the button labelled "Wizard", and in the box that appears paste the following:  barrier=* and foot=no

  3. Click on "build and run query" - the map on the right should now have lots of yellow dots - you can click on one to see details of it, and

  4. To export the points that you have found, click on "Export", then find the line "download/copy as GPX", and click on the word "download"

  5. This will give you a file containing .gpx waypoints that you can load into Osmand (on your phone, click on the gpx file, select "Osmand", and select import into favourites.

To update the OpenStreetMap data, you will need to go to https://www.openstreetmap.org and create an account. There is a very good walkthrough you can follow, which will appear the first time you click on the "Edit button" on the home screen (make sure you've zoomed in enough).

There is a very good wiki for OpenStreetMap (OSM) - https://wiki.openstreetmap.org/wiki/Main_Page is a good starting point.

There are pages of reading available, also https://learnosm.org/en/ also can help with some guides.

Just so you can get going;

Go to one of the barriers you think may be wrong, look at it and perhaps take a photograph. Have Osmand creating a track so you know exactly where you were when you found it (just in case location on OSM is slightly wrong).

Go back to overpass turbo search results, find the barrier, click on it, then click on the blue number at the top - you are now viewing the barrier (node) on the OSM website. Click on "Edit" and change the tags, if you think that is the correct thing to do - the wiki has lots of information. If for instance, the barrier can always be easily opened, perhaps the tags should be change to foot=yes (if this used by cycles - bicycle=yes as well)

Just a note about Timescales

When you edit OpenStreetMap, the edit is immediate, but it will not appear on Osmand until you update the offline map, probably early the next month when the update becomes available.

Good luck & feel free to get back in touch if I can help more.

Regards

Nick

OSM = Tallguy

[Greg Troxel]

Nick A <nick.a...@gmail.com> writes:

> Go back to overpass turbo search results, find the barrier, click on it,
> then click on the blue number at the top - you are now viewing the barrier
> (node) on the OSM website. Click on "Edit" and change the tags, if you
> think that is the correct thing to do - the wiki has lots of information.
> If for instance, the barrier can always be easily opened, perhaps the tags
> should be change to foot=yes (if this used by cycles - bicycle=yes as well)

Lots of good advice.

I just wanted to add that the OP should be a bit cautious in
"correcting" data. access tags are supposed to encode whether one is
allowed to do something, in addition to needing it to be physically
possible.

A rough road with a locked gate, in an area that is known to allow
hiking and bicycling would usually have a barrier node that is tagged
something like (but read the wiki!):

access=private
foot=yes
bicycle=yes

If the gate has a no trespassing sign, and is tagged foot=no or lets the
access=private flow down to foot, then it's correctly tagged.

Areas that are posted no access but where this is widely disregarded are
very difficult to map. There is a permissive tag, but I would not use
that with explicit no trespassing signs.

Another bit of advice is to look at the history of the node and see how
last edited it, and to write to them using the messaging function or to
comment on the changeset. This is especially true if they are local.

Also, make sure that you are using the correct profile in osmand. It is
supposed to, and in my experience generally does, use access tags for
the right mode of transport.

Note that my comments are made without having any understanding of
what's actually on the ground there or whether the existing data is
correct. I'm just cautioning to really understand the on-the-ground
reality and the tagging and not assume 100% "osmand didn't route me like
I want" implies "tag is wrong" because there are a lot of steps and
complexity in between.

[Klaus D. Günther]

Hi Nick,

many many thanks for your comprehensive response.

I have contacted "dornweg", the last mapper who has edited that barrier node, in the meantime, and I hope he will look at the numerous other barrier nodes with "foot=no" scattered all over the Odenwald mountains. I have never encountered a "lift_gate" barrier that has been closed not only for cars but also for hikers.

Another reason why a road may be avoided by the Osmand routing algorithm is when it has been declared as agricultural or silvicultural. Actually this means that it is closed for private cars, but open for hikers and bikers. But in OSM the latter fact must be declared explicitly, or else hikers and bikers will be excluded from such roads: rather misleading for osm mappers.

Regards,

Klaus.

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[Greg Troxel]

Klaus D. Günther <klausdg...@gmail.com> writes:

> Another reason why a road may be avoided by the Osmand routing algorithm is
> when it has been declared as agricultural or silvicultural. Actually this
> means that it is closed for private cars, but open for hikers and bikers.
> But in OSM the latter fact must be declared explicitly, or else hikers and
> bikers will be excluded from such roads: rather misleading for osm mappers.

It's just a fact of life that complicated access restrictions need
multiple tags.

Around me, there are things that are physically rough roads, where cars
are banned but bicycles and hiking (and horses) are allowed, and
access=private
foot=designated
bicycle=yes
horse=yes

is how the are or should be tagged.

If you are running into roads that just say "access=private" but really
are legally open to hiking/biking, then the tags need changing. I'm
not sure what you mean by misleading - access as a tag is meant to apply
to all modes, unless overridden by a mode-specific tag like foot=.

The good news is that you can fix all this up and have a map that works
right.

[Klaus D. Günther]

Thanks for the clarification. 

Am Fr., 8. Feb. 2019, 16:37 hat Greg Troxel <g...@lexort.com> geschrieben: