[GraphHopper] Dynamic routing for Crisis/Disaster Areas

[Peter K]

Hey Mark,

yes, downloading only the graph changes is possible at the low level -
there is currently no OSM changeset reader or similar.

But you already indicated that a fresh import is already better and so
... if you want to integrate your changes while import have a look into
the OSMReader where an edge is created via "graph.edge" and you can
manipulate the access flags too.


> I do not fully understand CH yet, but it seems to limit flexibility. I
guess it is a
> tradeoff between sped and flexibility.

Exactly.


> One option we have is to use CH on our servers and download the route
to the device??

Sure, you can do this too. But having the entire up-to-date graph (be it
with or without shortcuts due to CH) on the device probably makes more
sense in your case.

Regards,
Peter.


> Hi Peter
>
> Thanks for the response, because of the number of Android applications
> we expect to be out out in the field, I was considering  uploading
> changes to the road status to a database in semi real time (or when
> the responder returns to a point where they have wifi) then doing a
> new map on a once or twice daily basis, extracting the current road
> status from the database.
>
> The reason for this is to also pick up the data from the HOT Mappers
> who are incredible active, so we want that data on our Planning Site
> as well as downloadable on the devices, so that the responders have
> the latest information available to them
>
> I have to admit that I am not a Java Person, although necessity is
> making me devote some time to learning, so I thought I would ask the
> people with a great deal more experience than me to point me in he
> right direction to implement this.
>
> I do not fully understand CH yet, but it seems to limit flexibility. I
> guess it is a tradeoff between sped and flexibility. 
>
> One option we have is to use CH on our servers and download the route
> to the device??
>
> Also, I had not considered just downloading the graph changes, is that
> possible?
>
> Kind Regards
>
> Mark
>