Wrong route calculcation, no turning right is allowed.

[Damian Badura]

Hi,

Recently I notice that the calculated route is wrong.

Correct route on OSM using Graphhopper:

https://www.openstreetmap.org/directions?engine=graphhopper_car&route=50.26617%2C19.01935%3B50.26674%2C19.01933#map=18/50.26747/19.01898

In Application, the route is wrong, you cannot turn right in the crossroads:

Greetins!

[Xavier]

Which crossroads? Your statement is ambigious given that we can not
read your mind over the internet.

Now, assuming you meant a right turn from north bound Sokolska onto
east bound Michala Grazynskiego (note, I don't have the actual
characters in the names on my keyboard [US keyboard here], so these are
as close as I can easily type the names) then the cause seems to be
that there is no turn restriction in the underlying OSM data for that
crossroad.

The crossroad of east Michala Grazynskiego Sokolska has two turn
restrictions set on it.

#1: only right turn from east bound Michala Grazynskiego to south bound
Sokolska.

#2: no left turn from north bound Sokolska to west bound Michala
Grazynskiego.

Neither of which is a "no right turn" restriction from north bound
Sokolska to east bound Michala Grazynskiego.

So it looks like you have discovered a small amount of missing data in
OSM proper. So if reality on the ground at that intersection is "no
right turn" the fix would be to add the restriction yourself or ask a
local mapper to add the restriction. And once the change flows into
OSMAnd's map files, OSMAnd should then calculate a correct route as
well.

Note, I do not know why graphhopper calculates a different route.

I am not going to change the data myself, because I am half a world
away with no way at all to verify the reality on the ground at that
intersection myself.

[Damian Badura]

Hi,

Thanks for a long term accurate answer.

I don't know why I wrote right, but I mean left. Sorry for my mistake.

The problem is that you can't turn left from south Sokolska Onto east Michala Grazynskiego.

Generally you can't turn left from Sokolska to Michala Grazynskiego in both ways.

Graphhoper respect this restriction so OSRM do.

[Xavier]

On Sun, Jan 19, 2020 at 02:36:24AM -0800, Damian Badura wrote:
>Hi,
>
>Thanks for a long term accurate answer.
>I don't know why I wrote right, but I mean left. Sorry for my
> mistake.
>
>The problem is that you can't turn left from south Sokolska Onto east
>Michala Grazynskiego.

>Generally you can't turn left from Sokolska to Michala Grazynskiego in
>both ways.

Ah, ok, so only right turns are allowed from Sokolska onto Michala.

Looking at the OSM data just now, we have no left turn restrictions
from both directions on Sokolska onto Michala Grazynskiego.

So unless the data was recently changed (which the history shows no
recent changes) it does look like the proper turn restrictions are
present in the OSM data.

In which case, this looks like it might be a bug somewhere. So you
will need to file a bug report at the OSMAnd github issue tracker
(which is the official way to report bugs, reporting them here does not
get them before the developers in most instances).

The issues tracker is at: https://github.com/osmandapp/Osmand/issues