Best settings for prepare.min_network_size, prepare.min_one_way_network_size and routing.non_ch.max_waypoint_distance?

Open Source Routing Engine
1

Hi,

I’m importing graphhopper data in “hybrid” mode, and haven’t yet been able to find online information about three of the settings.

prepare.min_network_size
prepare.min_one_way_network_size
routing.non_ch.max_waypoint_distance

Currently our map data is Australia-Oceania and Europe-UK. Although we expect to add more regions in the future.

My config.properties are currently:

graph.flag_encoders=car|turn_costs=true
prepare.ch.weightings=no
prepare.lm.weightings=fastest
prepare.min_network_size=200
prepare.min_one_way_network_size=200
routing.non_ch.max_waypoint_distance = 1000000
graph.dataaccess=RAM_STORE

Can anyone offer any insights?

Many thanks,
Luke

2

Hi Luke,

your settings look reasonable to me. The network size describes the size of a disconnected network that will be removed during the import. Think of a small island, but these islands can occur in cities, for example private parking, there is no way to switch from the private parking to the road or vice versa.

The max waypoint distance is the max beeline distance of waypoints. If waypoints are farther away GraphHopper will reject the calculation, because the calculation would time out / run into max nodes.

Cheers,
Robin

3

Hi Robin.

Thanks for your quick reply! That’s very helpful and explains those settings very well.

Luke