Hi, I’m new to Graphhopper and I wanted to do an isochrone calculation. Download version 4.0 but when compiling the argentina-latest.osm.pbf file it is not taking the speeds that the PBF file has loaded. Can someone explain or guide me how to configure my profile so that the routes are the same as those found on the Graphhopper page.
What do you mean? Which speeds do you expect?
There are a few differences between the online version and the open source engine. This was discussed a few times in the past, e.g. see here: Different settings for commercial Directions API compared to open soure version?
For a certain route I get 30 minutes of travel when in reality it is at least 45 minutes of travel. Graphhopper takes speeds from OSM data or are speeds set by road type?
OSM data only contains speed information via the maxspeed tag, which represents the legal speed (limit). Because this maxspeed tag is neither available for the majority of routes, nor it is a realistic assumption for vehicles to drive at this speed all the time, GraphHopper uses ‘average speeds’ speeds for its route calculations. These are calculated based on various other tags like highway or surface. You can find this information in CarFlagEncoder.java and the other FlagEncoder implementations.
Can you share the specific route that you think should yield a longer travel time? There is always room for improving this and feedback is very welcome.