I noticed that for certain lat/lng the routing engine snaps wrongly to the closest road because there are very near roads at different altitudes (tunnels or bridges), causing a wrong route computation.
Is there any way to make the routing engine aware of the altitude to make more accurate the process of snapping?
Can I use snap_preventions in combination with CH? I mean, snap_preventions can be configured in the GHRequest object without affecting the speed mode right? Because I am using CH and I need to keep it for performance reasons.
Hi, I’m also facing the same issue actually. I think it’s not about the altitude but about multi-layer road (tunnels, bridges) and also the quality of GPS coordinates that we want to snap to the nearest road segment. @karussell - from what you are saying, does the snap_preventions only works for road type in OSM or I can also put like layer=1 or layer=-1 so graphhopper will prevent the GPS coordinates snapped with any road which has layer tag?