Import an existing graph

Hi everyone,
I’ve read that GrapHopper uses OpenStreetMap and GTFS data but can import other data sources. I was wondering if is it possible to import an existing graph? whether is possible, how should I do that?
Thank you

Generally speaking GraphHopper has different Reader implementations for different data sources, currently OSM and GTFS. If you want to load a different source the best approach would be to implement your own reader for your data type.

Importing a GraphHopper graph should be very easy and straight forward. On the first start GraphHopper will build a graph directory from your source file. With every consecutive start GraphHopper will use the previously imported graph instead of creating a new one.

Hope this helps?


Thank you, I will try that.

the graph that I want to import was done in OTP, should it work too? it is for public transit routing in UK, but OTP requieres a lot of memory and it is so slow.
Your help would be very appreciated.


I don’t know the details of OTP to be honest. GraphHopper can model a public transport network, including time schedule of trains/buses/ferries/…, so my general assumption would be that it should be possible. Orientate yourself at the GTFSReader and try if it will work :).

I would assume that having an OTPReader in GraphHopper would be a nice addition, so I think we would be very happy to see a PR for this as well :).


I do not know if and why we should read from some binary file. Using some configuration and the source files is the best approach IMO

how to import my own traffic data ?