ArcGIS 10.1 Network Analyst: Snapping stops from point-shapefile to route analysis layer doesn't work properly

Question

I'm struggling with a task, which should be not that difficult....but anyway I do not find a solution.

Background I'm map-matching tracks, generated by a GPS-device, to a road network. Therefore I make use of the ArcGIS 10.1 Network Analyst. I connected the GPS-Point measurements to polylines (1 for each track), created a buffer around them and made an intersection of the buffer-boundary with the street-network to determine point-barriers.

According to the paper of Ron Dalumpines and Darren M. Scott form McMaster University, Ontario, Canada I'd like to find the shortest path within the buffered area (confined by the generated point barriers).

Problem The problem I'm struggling with is the following: I'd like to define the stops (start- and end-point of the track) through a shapefile which contains the start- and endpoint for a certain track. The position of these points already coincidences with network-junctions points. Nevertheless ArcGIS seems not to be able, to link these points with the network and these "stop-points" get marked as "Unlocated".

If I use the default search tolerance of 5000 meters, ArcGIS is able to locate the stop-points....but the found ones are not at all the nearest ones to the position of the loaded shapefile.

Has anybody an idea what could cause this strange way of snapping? Has anybody already had a similar problem?

As a newbie I'm not allowed to upload pictures...otherwise I would have uploaded two pictures explaining my situation.

Thanks already in advance for your hints and advices ;)

Best Regards,

Dom

ETH Zurich, Switzerland

Answer 1

You need to check if your points which you will be using as stops are actually snapped to your tracks (they may appear as if they are snapped, but that is not always the case). Your connectivity settings may also not be correct.