"Exit left" / "Exit right" instructions

[devemux86]

Looking at the available turn instructions in VoiceHint, we do not have "Exit left" and "Exit right" instructions.

They are very useful when we exit motorways. Now they are replaced by turn (slight) left / right instructions.

[afischerdev]

These would be very specific instructions, but they are indeed clearer
I made a first test. Just replace keep left/right with exit left/right on leaving motorways.
Something like this:

testtrack0.2.gpx.txt

The problem will be the clients and their handling of the instructions.
In the test I changed all 'exit left/right' back to 'keep left/right' to be conform with the clients.
But I guess that is not what you want.

[devemux86]

@afischerdev thanks for the example.

I do not understand what you mean with the change back?

GPX nav trk format has the advantage that is declares the instructions as strings.
Clients that already support exit instructions (like Cruiser) can use it immediately.

Nevertheless, "Exit left / right" are 2 new instructions.
So we will need new ids in VoiceHint and they must be included in all BRouter response types (like geojson).
Then clients must update their BRouter response parsing to handle the new instructions.

[afischerdev]

@devemux86

Nevertheless, "Exit left / right" are 2 new instructions.

Yes, that is what I did. And as you see it is working for the Locus export (timode=2). But for all other clients the new tag ER / EL have to go back to KR / KL.

[devemux86]

@afischerdev

But for all other clients

Do you mean other turnInstructionMode?

Also are exit instructions available in BRouter test website?

[afischerdev]

@devemux86

Do you mean other turnInstructionMode?

Yes, and other exports.

Also are exit instructions available in BRouter test website?

Sorry, no. Not at the moment, it was just a quick local test.

[devemux86]

@afischerdev

and other exports.

Will it be available in all output formats: gpx, geojson, etc.?

[afischerdev]

@devemux86

Will it be available in all output formats: gpx, geojson, etc.?

If we don't protect them for unexpected result, yes. Please give me some time, I'll make a more usable example.

[afischerdev]

Now a first version is ready. But before coming out, here a short discussion:

During testing an the simple rule (change from motorway to motorway_link) this example comes up with exit left:

streetview first exit point
streetview second exit point

In my eyes the first point is not an exit, more a connection to next motorway.

And the BRouter database does not contain more info
point 1: highway=motorway_link surface=asphalt maxspeed=80 oneway=yes
point 2: highway=motorway_link maxspeed=100 oneway=yes

[devemux86]

@afischerdev

Do you mean that the exits should only be declared in instructions when change road categories?
i.e. change from motorway to motorway_link

[afischerdev]

@devemux86
It should only be declared on motorway exits.
But the rule goes with change from motorway to motorway_link and so it catches what you see above.
So no idea how to grab that at the moment.

[devemux86]

@afischerdev

Have you tested this area on other routers like OpenRouteService or Valhalla
to see what instructions they generate there?

[afischerdev]

@devemux86
Both using keep left, keep right
Only Google brings an exit announcement.

[devemux86]

@afischerdev

Both using keep left, keep right

Is it for the motorway_link to motorway_link example?

Because both routers have exit instructions.
Doing routings on motorway exits, they both produce exit instructions.

[afischerdev]

@devemux86

Is it for the motorway_link to motorway_link example?

Yes, it is. And Graphhopper as well uses keep left/right in this sample.

Because both routers have exit instructions.
Doing routings on motorway exits, they both produce exit instructions.

May be we find an example that contains exit in it.
Think I found one:

look here for BRouter
look here for Valhalla - with exit
look here for ORS - no exit, keep right

However, for BRouter we have no additional data to map an exit.
So it's either everything or nothing - everything is Exit or Keep left/right.

[devemux86]

@afischerdev

Graphhopper as well uses keep left/right in this sample.

GraphHopper does not support "exit" instructions (see here).

[devemux86]

@afischerdev

Sorry about the OpenRouteService, it does not support "exit" instructions (see here).

[afischerdev]

I think I found a solution for the 'exit problem' - the future voicehints are checked as well.
So here is a new output with exit Instruction only on last motorway point.

[devemux86]

@afischerdev Thanks for the PR, it seems to work ok. 👍
(tested json and gpx formats)

I included it into the latest Cruiser for more user testing:

• BRouter (offline) turn instruction improvements devemux86/cruiser#622 (comment)