The route time reported from GraphHopper is often wildly wrong.
Example with a simple route from 40.7644, -111.9261 to 39.0584, -114.0704:
openstreetmap.org - Car (OSRM): 363km / 3:36 hours
openstreetmap.org - Car (GraphHopper): 359km / 4:28 hours
This is the same for many routes, actually for most. Why does GraphHopper calculate so much more time than all other routing providers?
I tried contacting support about this, but they just stopped answering me. I don’t take that as a very positive sign either
There is something really strange that we have to fix.
they just stopped answering me.
We did not stop answering but some of us are on holidays and other support issues were either more pressing or just easier to answer. We will definitely look into these findings.
Just a simple “Sorry, we don’t have time to look at this right now, but we will look at it as soon as we can” would be an answer better than no answer
Thank you for acknowledging the problem.
Yeah … we thought we could give you a better answer faster but obviously failed.
Just to put my personal findings in here:
- Roads with speed limit in OSM appears to get the correct time
- Adding surface information (paved, asphalt, gravel etc) does not seem to have any effect at all
- Adding the correct road type however does have an effect
Disclaimer: I only made edits on roads I know the surface/type of
This was a huge improvement! Thanks!
Can you say anything about what you have changed? Are there any thing we can do in OSM to improve the calculation for areas where it might not be as good? What I’ve tested so far, looks much better than before, just nice to know.
Currently we have a few limitations of what we can store of the OSM data in the routing engine storage and mainly this limitations makes it hard to improve ETAs. We’ll further improve things in the next months e.g. country-dependent calculations are still too tricky so that we don’t do this on a wider scale.
Are there any thing we can do in OSM to improve the calculation for areas where it might not be as good?
You can help with tagging only in the sense that you can add the maxspeed, correct lanes and correct highway type.
What I’ve tested so far, looks much better than before
Great to hear this!