Re: [OSRM-talk] Example of restricted access flags for way_function and turn_function

[Mateusz Loskot]

On 1 July 2017 at 20:00, Michael Krasnyk  wrote:
> Hi Mateusz,
>
> for turn restrictions you can use
> https://wiki.openstreetmap.org/wiki/Relation:restriction  OSM tag.
>
> Here is an example
> https://github.com/Project-OSRM/osrm-backend/blob/e2e279bc852cd024aef1ad445a81bad2884902cd/features/car/restrictions.feature#L11-L34
> that  is similar to yours with nodes mapping w->A, j->B, e->C, w->D.

Michael,

The restrictions.feature sample turned exactly what I was looking for.
Thanks a lot!

Best regards,
-- 
Mateusz Loskot, http://mateusz.loskot.net

___
OSRM-talk mailing list
OSRM-talk@openstreetmap.org
https://lists.openstreetmap.org/listinfo/osrm-talk

Re: [OSRM-talk] Example of restricted access flags for way_function and turn_function

[Mateusz Loskot]

Daniel,

Thanks for the pointers. I'll check them in details.

So, I understand purpose of turn_function is to tweak penalty based on
restrictions.

I'm wondering about slightly different use case and I'm trying to
understand which
tool, way_function or turn_function or neither, is the right way to use.
Shortly, in my use case a restriction is related to allowed/disallowed
turn from one link to another.
Let's consider simple network.

C
|
B---A
|
D

Let's assume, all links are bidirectional ways.
Node B includes information about turn restriction like so:
- turning from AB link to BD link is disallowed
- turning from AB link to CB link is allowed

AFAIU, object in turn_function has no context related to B node and
adjecent links to,
eg. calculate artificial high penalty to effectively block AB to BD turn
I'm also not sure there is way to include necessary context details in
object passed to way_function.

But, perhaps I'm missing some advanced profile tricks here.
So, does processing of such restrictions fit purpose of turn_function at all?

One of feasible alternative approaches is to pre-process such network
splitting the B node to B and B-prim

A - B - C
C - B' - D

This would effectively disable travelling along A - B - D

I'll appreciate any comments.

Best regards,
Mateusz




On 1 July 2017 at 10:41, Daniel Hofmann  wrote:
> You are correct, the way function can set a "restricted" flag per way (and
> direction), which you can then use in the turn function to put a high
> penalty on turns from/to "restricted" ways.
>
> The general idea is outlined here:
>
> https://www.openstreetmap.org/user/happygo/diary/40564
>
> Have a look at ExtractionWay, ExtractionTurn and the EdgeBasedGraphFactory.
>
> Cheers,
> Daniel J H
>
> On Sat, Jul 1, 2017 at 12:08 AM, Mateusz Loskot  wrote:
>>
>> Hi,
>>
>> I'm trying to learn about use of the way_function result flags,
>> forward_restricted and backward_restricted, and their correspondence
>> with turn_function machinery, especially input source_restricted and
>> target_restricted flags.
>>
>> Is there any data and profile example which shoes these in action?
>>
>> I guess, way_function is called first and any of the restriction flags set
>> here for the link are passed to turn_function. Correct?
>>
>> Disclaimer: I haven't looked into OSRM implementation details yet,
>> which, once grasped, I guess, might be enlightening.
>>
>> Best regards,
>> --
>> Mateusz Loskot, http://mateusz.loskot.net


-- 
Mateusz Loskot, http://mateusz.loskot.net

___
OSRM-talk mailing list
OSRM-talk@openstreetmap.org
https://lists.openstreetmap.org/listinfo/osrm-talk

Re: [OSRM-talk] Example of restricted access flags for way_function and turn_function

[Daniel Hofmann]

You are correct, the way function can set a "restricted" flag per way (and
direction), which you can then use in the turn function to put a high
penalty on turns from/to "restricted" ways.

The general idea is outlined here:

https://www.openstreetmap.org/user/happygo/diary/40564

Have a look at ExtractionWay, ExtractionTurn and the EdgeBasedGraphFactory.

Cheers,
Daniel J H

On Sat, Jul 1, 2017 at 12:08 AM, Mateusz Loskot  wrote:

> Hi,
>
> I'm trying to learn about use of the way_function result flags,
> forward_restricted and backward_restricted, and their correspondence
> with turn_function machinery, especially input source_restricted and
> target_restricted flags.
>
> Is there any data and profile example which shoes these in action?
>
> I guess, way_function is called first and any of the restriction flags set
> here for the link are passed to turn_function. Correct?
>
> Disclaimer: I haven't looked into OSRM implementation details yet,
> which, once grasped, I guess, might be enlightening.
>
> Best regards,
> --
> Mateusz Loskot, http://mateusz.loskot.net
>
> ___
> OSRM-talk mailing list
> OSRM-talk@openstreetmap.org
> https://lists.openstreetmap.org/listinfo/osrm-talk
>
___
OSRM-talk mailing list
OSRM-talk@openstreetmap.org
https://lists.openstreetmap.org/listinfo/osrm-talk

[OSRM-talk] Example of restricted access flags for way_function and turn_function

[Mateusz Loskot]

Hi,

I'm trying to learn about use of the way_function result flags,
forward_restricted and backward_restricted, and their correspondence
with turn_function machinery, especially input source_restricted and
target_restricted flags.

Is there any data and profile example which shoes these in action?

I guess, way_function is called first and any of the restriction flags set
here for the link are passed to turn_function. Correct?

Disclaimer: I haven't looked into OSRM implementation details yet,
which, once grasped, I guess, might be enlightening.

Best regards,
-- 
Mateusz Loskot, http://mateusz.loskot.net

___
OSRM-talk mailing list
OSRM-talk@openstreetmap.org
https://lists.openstreetmap.org/listinfo/osrm-talk