Status of turn-restrictions in web-frontend engine

I am aware that the feature of turn-restrictions / turn-cost has been asked many times ago, and that it is not an easy job to implement this to the service at https://graphhopper.com/maps/

And some days / weeks ago I asked Peter how we can give some support for this “most wanted” (and maybe most-needed?) feature to be implemented.

Peter said among other points: “Try to make Graphhopper more popular”

I assume that Graphhopper would gain much more popularity if it gets an implementation for car routing on openstreetmap.org … So far we can find Graphhopper routing “only” for foot and bicycle, or not?

(Did you notice that a new routing provider has been included there silently, namely Valhalla by mapzen.com??)

But I (as a normal user) would recommend to include Graphhopper car routing only to main osm.org website only as soon as car routing has the feature of turn-restrictions.

In German language I would call this the famous “Henne-Ei-Problem” …

Maybe we can figure out what technical step has to be done first for this feature?

Is it correct that the latest developemnt about this is in (after browsing many github issues)
https://github.com/graphhopper/graphhopper/issues/270 ?

Greets, Stephan

See also Peter’s answer here at announcement of GraphHopper integration in OpenStreetMap.

Emux

(Did you notice that a new routing provider has been included there silently, namely Valhalla by mapzen.com??)

Sure

But I (as a normal user) would recommend to include Graphhopper car routing only to
main osm.org website only as soon as car routing has the feature of turn-restrictions.

Yes, exactly that is the reason it is currently not there.

Is it correct that the latest developemnt about this is in (after browsing
many github issues) https://github.com/graphhopper/graphhopper/issues/270 ?

Exactly, there is also a first step already here

Maybe we can figure out what technical step has to be done first for this feature?

Contraction Hierarchy needs to work for edge-based graph traversal too, which is not that complex but a huge effort and will take 3-6 weeks.

I once thought about a crowd funding campaign about this, so that potential interested (commercial) users would sponsor only a small fraction and I would not need to take the riscs and costs of this feature. But before we start with this campaign we need to make main parts of flexibility work happen.

i was going to ask about turn costs, don’t have to now :wink:
please make it configurable whether left or right turn is more expensive, if it was autodetected or had a list, even better.

Now this is possible via a “workaround” and we’ll highly likely follow the good example of kurviger (that already have this feature live) once we find a good UI/UX for it to enable this.

Though I cannot follow the mentioned workaround immediately, I tried something derived from your blog posting at

So when accessing the normal main web service without any login via https://graphhopper.com/maps/

I can append the parameters &ch.disable=true to have online routing in car profile with turn-restrictions now.

After some first tests, it seems to work indeed. Many thanks!!

And appending &algorithm=alternative_route&alternative_route.max_paths=3 now enables the alternative route feature for the main web service. Also very useful!

So I say sorry for my low graphhopper interna knowledge, but what prevents us from having these parameters enabled by simple checkboxes or similar in the user interface on https://graphhopper.com/maps/ ?

Stephan

Thanks for the update and good to know that many stuff is working now for you better :slight_smile:

nothing but the lack of sourcecode :wink:

Also I would avoid having several checkboxes immediately accessible, instead I would like to have a gear icon for ‘advanced settings’ where one could change something like this. But creating a simple, good looking AND powerful UI is really hard and costs time.