0.5.0: Connection between locations not found

Open Source Routing Engine
1

I have an issue which I cannot reproduce on graphhopper.com.

I have a specific coordinate from which I am unable to get any directions from. The error is always “Connection between locations not found”. Other locations in the area is no problem.

It is specifically this location: https://www.openstreetmap.org/node/342523660#map=17/55.86225/9.84607

It tried finding the nearest node via locationindex, but t is a oneway street in the wrong direction:

But it is working on graphhopper.com/maps (using another way out)

Can anyone help me to figure out how to make Graphhopper that?

JDK 8, Graphhopper 0.5.0, Mac OS X

2

Link to Graphhopper Maps showing the correct way out:
https://graphhopper.com/maps/?point=55.8621%2C9.844776&point=55.863475%2C9.840844&locale=da&layer=Omniscale

3

You can try to play with the settings “prepare.minOnewayNetworkSize=200” or decrease “prepare.minNetworkSize”, this way the router does not get stuck in an (oneway) island. See also discussion here

4

Awesome. I’ll try that later today.

Thanx

5

After checking it out via street view, it turns out that the data is wrong. The road is blind, not one way. :slight_smile:

But thanks for the help. It is appreciated.

6

I resolved a lot of my ConnectionNotFoundException by changing that value to 200. But is there documentation on what that change does? And specifically, are there any performance issues to be concerned about?

7

Good question, I explained it shortly here: “Connection between locations not found”

1 Like
8

Are there any performance concerns by increasing minOnewayNetworkSize? I’m at 200 right now and am considering going higher.

9

The road network in OSM is not fully connected, so there are sometimes ‘islands’ of roads that cannot be reached from the rest of the network. The parameter just defines below which size these islands get removed from the network. So it does not necessarily affect the overall routing performance, but obviously it changes the routing calculations if the routes are close to these disconnected areas (because they might be completely removed from the road network)

1 Like